Band are or is?

In general group entities such as corporations, organisations, teams etc are seen as singular in the US but plural in the UK. I reckon this probably applies to bands as well

Number agreement for [collective nouns](https://en.wikipedia.org/wiki/Collective_noun) like "band" varies between different dialects of English and also sometimes varies by context. Generally, in American English the word "band" takes singular verbs, as do the names of bands, so American speakers would usually say both "this band is great" and, for example, "Metallica is a great band". In British English it varies more – British speakers would usually say "Metallica are a great band" but whether they would say "this band is great" or "this band are great" can vary from person to person or from situation to situation. An exception to that American and British distinction is when the band name is a plural noun with "the" in front; both American and British speakers would say, for example, "The Strokes are a great band", because that's a plural noun with "the" in front.

There is a pretty standard difference between BrEng and USEng here. In the UK we refer to an entity like a company, band etc. as a single unit, and thus it would be ‘is’. In the US, it is more common to refer to them as a collective of individuals, and thus use ‘are’. 

American English: is British English: are American English treats groups of people as grammatically singular, whereas in British English they are grammatically plural. This includes bands, institutions like governments/police, and sports teams. This content creator is Scottish, so "are" is correct in his dialect.

Everyone being like "American this" and "British that" honestly either is fine. There is a cluster of words in English that are ambiguous as to whether they're singular or plural. Most any word for a group of people behaves this way - it's about whether you're talking about the group as a unit or about the group as multiple individuals - think of it in terms of pronouns: "You're looking for the Marketing department? It's down this hall, on your left." "You're looking for the Marketing department? They're down this hall, on your left."

Because they used the singular “this”, British English uses the singular “is” to match the determiner. If they had used the ambiguous “the” then British English would use “are”

In British English, it’d be “This band is awesome!!”, but in general, ‘Band’ can use both depending on context. 2 examples are: . The band is my favourite! . The band are going on tour! (Still uses the ‘s suffix if you were to abbreviate it.)

I always thought both were acceptable (UK). Sometimes there can be nuance in unifying v.s. pluralising

“The band” is singular, so “Is” is correct. It depends on context though. If you say: “the band are all going bezerk backstage!”, you’re referring to the members of the band, so plural works. If you’re treating the group as a compound unit, then use singular. If the name itself is plural, it takes the plural form. The Dallas Cowboys ARE a good football team. So are Tottenham Hotspurs. Arsenal is, so is Dallas. The Beatles were a pop band, so are The Strokes. Steely Dan is a band, as was Led Zeppelin.

British English is more likely to use plural verb agreement with collective nouns. This applies to bands, sports teams, etc. Americans will tend to use singular forms with those unless the name of the band itself is plural like “The Beatles.” Americans and Brits will both use “they” and plural verb agreement when referring to collective nouns using pronouns.

This polish band is awesome or polish bands are awesome. Is for singular and are for plural

If band is plural in British English, shouldn't it be "These Polish band are..."?

I would say in my experience it depends mostly on context and where people are from. Like others have said, British English and American English differ the most here but I can remember cases where I’ve said “When are they [the band] coming on?” Followed later by, “this band is great!” So it kinda depends a little on what exactly you’re saying and in what context. Basic rule of thumb would be in American English, treat it as a singular and in British English treat it as a plural.

Band is singular, so "is"

Other people have given great explanations in the comments, but I feel like, in this case, saying "This xxxx are" doesn't sound quite right as 'this' is singular. Without the adjective, though, it would be 100% correct.

Generally, since you’re talking about one single band, you’d most likely use a singular verb. Even though “band” refers to a group of people, when referencing only 1 single group, the subject (usually) reverts to singular, so the verb and context is (usually) singular. Examples: - “those birds are flying west.” (Multiple subjects, plural) - “that group of birds is flying west.” (One subject, singular) - “those two groups are flying west.” (Two subjects, plural) But there are exceptions of course, as stated in the other threads. Exception examples: - “That band is great! They are my favorite. What time do they start playing?”

Whilst other commenters are correct, they're leaving out a lot of context that may be helpful to know for an English learner who doesn't just subconsciously know all the nuance of American English. Yes, in British English this would sound normal and in American English it would sound odd and unnatural, but not because you can't say "This band are..." In fact, there are situations where saying exactly that would add meaning to the sentence. This is because American English speakers love to treat singular, collective nouns as plurals when they're referring to the collective as a group of individuals. Thus, "This band *is* awesome!" but "That band *are* the biggest assholes on the planet." Note how the conjugation change actually imparts meaning to the sentence—by pluralizing the verb the band becomes individuals rather than a vague entity that includes works, people, and performances. This isn't something you have to learn, but it is a subconscious practice I've noticed in myself and other native speakers.

This might be different in the USA, but in the UK it is definitely 'is'. 'Are' would be used if there were multiple bands. You would, however, use 'are' if you used the name of the band rather than describing it.

I would say this polish bamd is awesome ❤️

"Is" seems more natural to me, but "are" doesn't seem that weird.