what's the difference

You might be thinking "must have" means "should have", but it doesn't; it means that that's your conclusion. E is the only one that expresses "should have" to contrast with "but wasn't".

Here "must" implies inference/deduction, which the writer of this sentence is not doing. "ought to" basically means "should".

If I'm correct, it is the only one that expresses obligation

"Must + have been" means you are 100% certain/sure of something. It's a contradiction to say "I'm sure he was wearing safety googles, but he wasn't". Ought to = should. "I should have been studying, but I wasn't". No contradiction.

A: He could've been wearing ... means "I don't know" but the sentence says he wasn't B: He must've been wearing ... neans I'm 90% sure, but the sentence says he wasn't C: He had been wearing ... is a fact about the past, but the sentence says he wasn't D: He should be wearing ... is an expectation about the present, but the sentence says he wasn't, not isn't E:He ought to have been wearing is an expectation about the past

I would have instinctively picked answer A. Am I correct in assuming that that would be permissable in everyday speech albeit with a slight snark?

"He must have been wearing safety googles", means you don't know for sure but assume he was wearing them based on the context. Like, "he must have been wearing a hard hat because he survived a brick on the head". "He could have been wearing" safety googles, but I don't know. "He had been wearing but wasn't" doesn't make sense. What you want to say is that the rules say he has to wear safety goggles, but he wasn't. So he "should have been wearing". "Should be wearing" isn't grammatically correct (not the right tense), so your only option is E) ought to have been wearing, which is a synonym of "should have been wearing".

"he must have been wearing" = I am logically deducing that he wore __ because of some evidence "He ought to have been wearing" / "he should have been wearing" = he is required/supposed to wear __ because of a rule/safety guideline/etc

- could have been: it was a possibility - Example: He could have been wearing safety goggles, but we don’t know for sure because everything was destroyed in the explosion. - must have been: based on the evidence, we conclude that this is what happened - Example: I didn’t see the accident happen, but he must have been wearing safety goggles because his eyes weren’t damaged by the hot steel. - had been: a statement of known fact - Example: I saw the accident happen. His eyes weren’t damaged because he had been wearing safety goggles. - should be: expresses the right thing to do in the present - Example: You should be wearing safety goggles right now if you don’t want to damage your eyes. - ought to have been: the same thing as “should have been”. Expresses the right thing to do in the past, although this thing didn’t happen - Example: He ought to have been wearing safety goggles, but he wasn’t, so his eyes were damaged.

E is the most correct answer, but I would argue A works as well. The important thing is the implication that he wasn't wearing safety glasses.

"Must have been" usually means "we conclude it was that way." That is, "he must have been wearing safety goggles" means "he was certainly wearing safety goggles", not "it was bad that he wasn't."

I would add as a side note: in modern American usage, “ought to have” is very rare. Most Americans would say “should have been wearing” in this instance. An exception is in the Appalachian regional dialect, where “ought to” is still quite common. I speak from Appalachia with a very mild accent, and the usage of “ought” is one of the more common ways people can place my dialect because it’s so uncommon outside of Appalachia. As an American, I also hold the stereotype that “ought to” is also common in British dialects, but I’m unsure how accurate that is.

i’m glad we found a test that isn’t just straight garbage and actually gave the right answer

"Must" \[past tense/present-continuous tense\] = "there is no other possibility"/"I am extremely sure that" "Must" \[future\] = "will be/are forced/required to" I can see where the confusion arose, as "You must wear your safety goggles" is a requirement/command, but when you use "must" referring to the past or present, it's a belief, not an imperative

"must have been wearing" implied that, based on what you are told, you think with high certainty he was wearing glasses. "I believe he was wearing" is roughly what it means. When using "must" in the past tense we do not speak of obligation or necessity, but rather of assessments. Must in present and future tense does speak of obligation "You mustn't break the law". The correct option is indeed "ought to have been wearing". This implies that there was a need or obligation for him to wear glasses, but didn't. The "should have" option most people would also understand, but should has a wider array of meanings and could cause confusion.

For what it's worth, in some languages, the same word gets divided into 2 or 3 in English.... Ought/should, must, owe... Romance languages get this from Latin debere. Your native language may not distinguish ought from must like English does, and there is a big difference. Latin hope (sperare) is the same way, as it also means wait. We rarely interchange those two words in English though. This does go the other way, too. English will use one word for concepts that are divided up into 2 or 3 words in other languages (to be, to know, to have).

Must have means you are sure 100% that happened in the past

"Must have been wearing safety goggles" implies that, as far as you know, he was wearing the goggles. The rest of the sentence contradicts this by explicitly stating that he was not wearing the goggles

I’ll never understand the purpose of such quizzes. In a normal setting, the correct phrase would be "should have worn" or, depending on the intended emphasis, possibly "should have been wearing." Both are more natural and commonly used. While I understand that the goal is to test modal verb structures, there are far more valuable things to teach than overly specific sentence constructions that rarely appear in everyday language.

i've been learning english my whole life and still struggles to understand "ought" lol

"must have been" is equal to saying "the situation must have been the case that" It's looking at the evidence and determining what the events of the past must be. This is what happened by my reasoning. It's the difference between: 1. I have concluded that it did rain in the past. 2. I declare that it should rain in the future.

“Must” is a statement, saying he did wear the goggles. “Ought” means he should have worn the goggles

Example: His face was badly burnt from the accident but his eyes were undamaged. He must have been wearing safety goggles. I didn't observe him wearing the goggles, but I'm sure he did indeed wear them, because his eyes didn't suffer any damage from the accident.

While "ought to have been" is correct, a more common way to express this is "should have been." The word "ought" is slowly falling out of usage. "x must have been y" is used when the speaker believes that "x was y" is true. It's also sometimes used to express surprise or doubt about a negative statement. Here's two examples: "Maybe James knows what happened at the event. He must have been there." Someone may also use the phrase like this: Speaker 1: "I don't believe William was wearing his glasses." Speaker 2: "Surely he must have been." (This second statement can be expressed with surprise or doubt, or even posed as a question.)

In what fucking universe are we still using "Ought" in day to day language. That looks like it's there just to trip people up. Though E is right. If it was "Mustn't've" then you would have been correct.

He "should have been wearing", while not presented as an option, is more idiomatic.

Must have been wearing = (almost definitely) was wearing Ought to have been wearing = (almost definitely) was NOT wearing (but was supposed to be wearing)

This is also an issue of tense.

“Must have” means the only logical conclusion is that he is wearing safety goggles, but because we learn later in the sentence he wasn’t, choice B should be eliminated

He could have been wearing * This suggests a possibility, but the sentence implies a missed obligation, not just a possibility He must have been wearing * This suggests with certainty that he was wearing the goggles, but the sentence clearly states that he was not wearing the goggles He had been wearing * This describes him as wearing the goggles happening before another event, but again the sentence clearly states he was not wearing them. He should be wearing * This is present tense, while the sentence clearly refers to a past mistake He ought to have been wearing * Expresses a missed obligation or recommendation in the past. It implies that wearing safety goggles was the correct thing to do, but he failed to do so

While "must" can be used as a somewhat stronger version of "should" with the "have" their meaning will not be so similar, while "Should have" is still about obligations/advice. "Must have" is about certainty about how an event happened.

Tense and intention. The only option that's in the proper tense and indicates that he was not wearing the safety goggles is e.

The right answer is E. A is wrong because "could have been" implies that you don't know if he was or wasn't wearing the goggles. But the second part of the sentence clearly says that he wasn't, meaning we do know whether or not he was wearing the goggles. B is wrong because it implies that you believe he was wearing the goggles. But the second part of the sentence says that he wasn't. C is wrong because it states outright that he was wearing the safety goggles, even though the second part of the sentence says outright that he was not. D is close, but still wrong because "should be wearing" is present tense, while the rest of the sentence is past tense. E implies that if he had done things the proper way, he would have been wearing the safety goggles. However, he did not do things the proper way because he wasn't wearing his goggles, leading to his injury. I hope this helps. 

"must" in this context means "is certain to" (eg. It must be answer E) rather than "was obligated to" (eg. you must wear safety goggles while handling hot steel). It's easy to understand how that is confusing though.

Could have - This is wrong, because in this context, 'Could have' involves speculation about the scenario, rather than describing fact of the scenario. Must have - This is wrong, because 'must have' is not only speculative, but doesn't align with the sentence. 'Must have' in this context means something equivalent to saying "of course he was wearing safety goggles". But that doesn't add up, because the hot steel damaged his eyes. Had been - Wrong, because this describes the fact. Unlike 'Must have', this suggests he was, factually, wearing the goggles in the scenario. In that way, it's an even worse answer than 'must have' which is purely speculative. Should be - This is wrong because it shifts the scenario to taking place in the present, rather than the past. You can know the scenario happened in the past, because of words like "wasn't" and the fact that "damaged" is the past tense. 'Be' refers to the present, not the past. Ought to have - This is another way of saying "Should have", and refers to the past. So it fits with the rest of the sentence **and** makes sense in context. If she "should have been wearing" the goggles, we're saying he did something wrong. And we're right! His eyes were damaged by the hot steel.

A is more ambiguous in this scenario, making it less appropriate when describing what "should have been done". It can work in a more informal setting, where the speaker is mocking the subject, but it doesn't fit with the second half of the sentence. EX. "Was he wearing safety goggles?" "He could have been wearing safety goggles... but he wasn't." B implies the speaker has inferred something that has occurred, but this is contradicted by "he wasn't", so it doesn't make sense logically. E is the correct answer. The sentence is framed as a criticism of the subject, framing the correct behavior that should have been done, making the use of "ought" the most appropriate choice

Must have done/been doing sth = assumption Ought to have done/been doing sth = obligation could have = possibility Should be = obligation but since it is not should have been wearing it is not correct here had been wearing = past perfect, it does not fit in the sentence and the use here.

The fact that this is a B2 level question really supports my theory that, in comparison to learning other languages, the A levels of English are super easy, but the B levels break people because of stuff exactly like this.

It would help to know your native language. In addition to all the good answers here, "must" is a confusing word for speakers of romance languages. For example in Italian, the English phrase "I must go" or more commonly "I have to go" is translated as "Devo andare" where "devo" means "obligated". But in English, as in this test, "must" can also mean that you are drawing a conclusion and so would not be translated as "devo" (I'm not sure of the correct translation.) It's particularly confusing in the negative. I had to explain this to a German friend who wanted to say "You don't have to go" but she said "You mustn't go."

More than one of these could be correct based on context: A. Implies that it was possible that they could have worn the glasses. And sounds like the person speaking is scolding them. B. This is a contradiction, meaning that the speaker had every reason to believe that the person was wearing glasses, but it was revealed as fact that they weren't. The speaker is surprised by this. This has a more jarring effect on the flow of the statement. C. This is the most incorrect. The "but wasn't" would need to be followed by something to specify the timing, or spoken with extremely hurried and dramatic effect. For example, "He had been wearing glasses, but wasn't [at the time], ..." D. The speaker expects the person to be (still) wearing glasses as a consequence of previously wearing them. E. The "most correct", though I would expect A to be more common with someone who is angrier at the person who hurt themselves.

I would’ve said D, but E would work too, it’s just not my natural way of speaking

A better answer would be “Should have been wearing”, but that isn’t one of the choices. Choice E is the next best correct choice (although it is overly complex and awkward).

About 20 points IQ

B)-Must have implying without knowing he was, and the correct answer A)-Could have implying he should have been wearing googles if he was responsible but unfortunately was not.

Ought to is the past tense of must and the sentence is in past tense, so E is the grammatically correct answer.

In the simplest explanation... Must have been = a very strong 'guess' (by inference/deduction) Ought to have been = Should have been = a criticism/regret (in this case, criticism) In the example, we know he was not wearing goggles.. so it's not a guess... here, they are criticizing the person.... For me (36 years old), 'ought to have been' is a bit dated and I would always use 'should have been' instead. Just personal choice, though.

I would say "should have been wearing," rather than any of the answers. E would sound correct, but old-fashioned.

“Must have been” means that you have evidence leading you to believe he was wearing them, but the next clause says the opposite.

This is a tricky one. **Must** can mean a requirement. It would be correct to say, "Wearing safety goggles is a **must** in the lab environment". However, when used in the context of your answer, **must** is being used as a strong assumption - something that we believe had to be true even though we didn't observe it. For example, "Johnny **must** have been working hard in school today, because his homework is already finished". In your example, we know he damaged his eyes, so we know he **must not** have been wearing safety goggles. A) **Could** has two potential meanings. It could be an optional requirement, so he **could** have chosen to wear goggles or not. From context, we know this is not an option in lab environments. It could also be an uncertainty about whether we was wearing goggles or not. We know this one is not true because the sentence says he was not. C) This one tells us he had been wearing goggles, then tells us he wasn't. Contradictive. D) **Should** means strongly suggestive or a requirement that wasn't followed. This one is close, but it is in the present tense while the rest of the sentence is in past tense. E) This is correct because **ought** means that this is the expectation or requirement that has not been fulfilled. As an American English speaker, I would understand this as the correct response, but **ought** is an uncommonly used word in the United States, though probably normal in British English. I would have said, "He **should have been** wearing his safety goggles, but he wasn't, and as a result, the hot steel badly damaged his eyes. This is different from D because it is in the correct tense.

A could also be correct, but only in a snarky/sarcastic scolding way. For example: "He could have been wearing safety goggles, but no. He decided it was a *great* idea to *not* wear safety goggles, actually. And so he was awarded the generous gift of a hot piece of steel in his eye. What a great idea!"

A) "He had the chance to wear safety goggles" (with the implication that he didn't) B) "He was wearing safety goggles" (with the implication that the statement is based on other evidence rather than the speaker knowing for sure). Doesn't work because the result of burned eyes can't logically come from you deducing the evidence wrong. C) "He was wearing safety goggles" (before a certain event). Doesn't work because it contradicts the next clause. D) "He is required to wear safety goggles" (with the implication that he isn't). Doesn't work because it contradicts the past tense of the next clause. E) "He was required to wear safety goggles" (with the implication that he didn't). Between A and E, E is the better choice since working in a dangerous environment typically \*requires\* you to use proper protection.

The outcome was negative...

The correct answer should be E) “ought to have been wearing.” Explanation: The sentence suggests that wearing safety goggles was the right or expected thing to do, but he didn’t wear them, leading to an accident. • “Ought to have been wearing” (E) expresses a moral obligation or a strong recommendation in the past. It means he was expected to wear goggles but didn’t. Why not the other options? • A) “Could have been wearing” → Means he had the possibility, but it doesn’t imply obligation. • B) “Must have been wearing” → Implies a strong certainty that he was wearing them, which contradicts the sentence. • C) “Had been wearing” → Suggests continuous action before another event, but he wasn’t wearing them. Answer D) “should be wearing” is in the present tense, which makes it incorrect for this past context. So, E) “ought to have been wearing” is the best choice!

In this context, '*must* have been', is like a logical 'must', rather than a normative 'must'. Like, "I logically infer that he was in fact wearing safety goggles." or "It is impossible for him not to have been wearing safety goggles."

It's the difference between colloquial and formal usage. Formally, it cannot be "must". Because then what happened couldn't have happened. Indeed he "must not have".

Sounds very British

Wouldn’t it be should have been wearing?

You should start learning English from 0.

Must have been wearing, basically means he was wearing. It doesn’t make sense in this sentence. An alternative sentence where it would make sense: He must have been wearing safety goggles, because his eyes weren’t damaged when he was hit in the face by hot steel.

“Must” has more than one meaning. It can be a command or a supposition. The meaning in which it’s a command only works in the present tense. Thus, the difference between: You must wear protective goggles, because this activity is dangerous. (“must” is part of a command) and You must wear protective goggles, because you have great eye health in spite of all the welding you do. (“must” is indicating the speaker’s supposition) can only be distinguished by context. But in the past tense, the meaning in which it’s a command is no longer available, and the sentence you picked indicates that the speaker supposes that he was wearing protective goggles.

"must have" is deduction or inference. "ought to have..." is the only correct option because it talks about an optimal, desired outcome. He wouldn't have damaged his eyes if he had worn those god damn goggles! So he ought to have been wearing them... can't say we didn't warn him.

Even though E is right, would you normally not just say: He should have been wearing.?

"Must have been" puts the obligation on you (to guess correctly). "Should have been" puts the obligation on him (to act correctly, but he failed).