請問 A few 和few 有什麼分別?

There is a difference between little and a little, and between few and a few. Without a, little and few usually have rather negative meanings. They may suggest 'not as much/many as one would like', 'not as much/many as expected', and similar ideas.
The average MP has little real power.
Few people can speak a foreign language perfectly.

A llittle and a few are more positive: their meaning is generally closer to some. They may suggest ideas like 'better than nothing' or 'more than expected'.
Would you like a little soup?
You don't need to go shpping. We've got a few potatoes and some steak.

a few幾個;為數不多的;有一些
few很少數的;幾乎沒有的