is there a way of not getting confused with these body parts?

Probably not what you want to hear. But if you referred to your forehead as a foreskin I would giggle 😅 it is an innocent mistake that is a little risqué rather than rude. These are words that don’t come up a lot in conversation so probably difficult to practice - unless you are a doctor and need to use them all the time.

Same way people don't confuse someone called Krystal with the name Kirsten. Or Lausanne, Switzerland with Lucerne, Switzerland. Or any other words/names with similarities. They practise. You can also use word association tricks. For example, I could never remember what the dash above vowels that goes down is called (i.e., a grave). Untill I came across the French word 'grève'. Grève and grave sound similar, so now I say a little jingle in my head that goes "grève has a grave" to remember what it's called. So for your first example, maybe you could think about the fact there's a lot of loose, extra skin down there (at least, there is for the uncircumcised), but the skin on your forehead is quite tight and there's no extra skin. So fore*skin* is the word for where there's a lot of loose skin.

I'd be inclined to say "uncle" too if I kept mixing up my foreskin with my forehead. >!For the English learners, to 'say "uncle"' means to give up. Typically in the contest of wrestling. Which makes the OPs comment mildly humorous.!<

It may help if you understand the deeper meaning of the words. "Fore" means towards the front, from the same root as *forwards*. The forearm is the part of your arm at the front. From the elbow to the wrist. The forehead is the part of your head at the front. The foreskin is the part of skin at the front of that appendage. Animals such as horses have two forelegs and two hind legs. I don't know if it helps or confuses things that they also have four legs! Tennis has forehand shots (using the front of the racket), as opposed to backhand. We forecast tomorrow's weather; seeing clouds in the foreground might give us a sense of foreboding. Note, it's all "forwards" things - moving forwards, looking into the future, in front of us. The cheeks on your face are fleshy, and there's two of them, so it's similar to the cheeks on your bottom. An arse can look a bit like a face, if you stick eyes on it. I can't help much with uncle, ankle and knuckle because literally *everyone* - native-speakers included - mix up similar sounding words. It's just something that you improve through practice. For a zillion amusing examples, see r/BoneAppleTea

Word associations are quite helpful when, on their own, they might be difficult to remember. The nice thing about the word “cheeks” on its own is that it can actually refer to both the buttcheeks and the cheeks on one’s face. You can safely just use “cheeks” and 99% of the time someone will understand you mean the cheeks on the face.

I'm gonna get downvoted for this, but I can't help myself. If you don't want to have to remember "foreskin," move to the US.

I'm sitting here, scratching my furrowed foreskin, wondering how you could get so confused. I hope you don't mind that little bit of buttcheek in my response. I understand the forehead/foreskin thing more readily because automatic pilot can easily take over once you've started articulating. I'm more confused about the buttcheeks. Does it sound too much like "bocca" or similar Romance words for mouths/cheeks/faces?

Take your hand. Slap your head. Say "forehead". Now slap your junk. Say "Foreskin". Do this, repeatedly. You can do this with pretty much any other body part pair you're mixing up, too. Although, the knuckles and ankles drill won't be nearly as arousing.

As a native speaker, it took me ages to learn the difference between vulva and uvula, so you can at least rest assured that you're not alone

Many of your mistakes, like chicken and kitchen, sound like you're just speaking faster than your brain can catch up. Practice can help - things like singing "head and shoulder, knees and toes" and your own made up additions to it can help. For problem words, especially the embarrassing kind, you will have to slow down your speaking and consider your word choice until you break the habit of using the wrong word first.

Stop saying forehead at all, just say head, brow, or temple(s). Also stop saying butt cheeks, just say butt, or cheeks when you are speaking about the face.

Funniest thing I’ve read all day.. the idea of mixing up forehead and foreskin especially. Not making fun; I totally understand as i used to mix up German words Bohne (bean), Baum (tree), Bein (leg) and (bone) Knochen. Practice makes perfect I guess. GL

What if you start looking in the mirror every morning and saying, “this is my forehead and these are my cheeks” or something similar. You could even say good morning to them if you want to be silly.