The English is very weird.
- The skirts are small, but the skirts are little, c'mon, no natural English speaker would say that.
Came here to say this. I couldn't answer "the skirts are small", only "little", which feels very wrong in context. I don't know why, just know that it is. I don't think I ever see it used as an adjective in a "[noun]=[adj]" way. Maybe as an adverb, or in the sense that "little"="young", but even if you can say "a little book", you don't say "the book is little."
I'm assuming you are asking for English:
While they are synonyms, they do carry different connotations and in some cases you can only use one of the three. It's really hard to explain but I will give it a shot
Small is used to describe a solid object or an "amount of" something that can be measured, you can have a small child but not small milk. However you can have a small amount of milk
Short is used to describe height or length or a one dimensional measurement. A short race, a short person. Colloquially it can be used to communicate a lack of supplies. My restaurant is short on napkins.
Little is much more generic, you can have little milk, a little child, little napkins, little races and little people. Those pairings may have different meanings depending on the context.
If you want to stay on the safe side use small for describing how much room an object takes up in space, short to describe height or length and little for anything else.
I agree, though I think it's worth pointing out that there is very often a difference of how we feel about something when choosing whether to use "small" or "little" in relation to size. The first is more emotionally neutral; the second conveys more feeling, especially when used with another adjective. "A small boy sat in the corner" vs "What a clever little boy!" Notice also "A small black dog" but "An angry little dog" etc.