few / a few / little / a little
There are only a few cookies in the box.
She invited all her friends, but few went to the party.
I'm sorry I can do little for you. 真抱歉，没法帮你做什么。
I still have a little money left. 我还有剩下一些钱。
The test was difficult, so few students passed.
I can't explain this complicated problem with only a few words.