A man ‘s sweater/ men’s sweaters
Mariia Redchuk, you are very helpful normally, but sometimes the grammar of our two languages simply don't match. In English it is ungrammatical to say women's when referring to a singular noun.
"Women's" means "for women to wear". It does not mean "belonging to a/the woman".
"A woman's shirt" would mean "a/the shirt belonging to a woman" and not "a shirt made for women". That would be "a women's shirt".
You are simply wrong. If you had enough experience of English, you'd know that we never say "a women's shirt", so your attempts to assign a meaning to it are hopeless, however much logic you may try to apply and however logical it may seem to you.
Why I have to enter "a women's overcoat", but "a men's shirt" is wrong?
It's not wrong here. What exactly was your input?
It said man's shirt and men's shoes.
It said? Or you typed in? Here it says "Men's sweater, men's shirt"
Aargh! Apologies for my grammatical error; the grammar of our two languages doesn't match...