We use “some” to talk about a quantity or number without being precise.
There are some apples left.
Would you like some tea?
When do you use “some”?
- with affirmative sentences
- in questions when the answer is probably yes
- with offers and requests
We use “any” to talk about a quantity or number that may or may not exist.
Have you got any suggestions?
I have never had any problems.
When do you use “any”?
- in questions (remember, if the answer is probably yes, you use some!)
- in negative sentences (with not or never)
We use “each” and “every” to talk about all the members of a group of people or things.
Each = “every one, regarded individually“.
Every = “every one, regarded as a whole“.
You can do an each/every exercise here.