look (at), watch and see

1. See is the ordinary word to say something 'comes to our eyes'

• Suddenly I saw something strange. Can you see me?


• Did you see the article about the strike in today's paper?

See in not used in progressive tenses with this meaning.
When we want to say that we see something at the moment of speaking, we often use can see.

• I can see an plane. (NOT I am seeing....)

2. We use look (at) to talk about concentrating, paying attention, trying to see as well as possible.

Compare

• I looked at the photo, but I didn't see anybody I knew.


• Do you see the man in the raincoat? Yes .
  Look again. Good heaves! It's Moriaty!

We use look when there is no object, and look at before an object.

Compare

• Look! (NOT look at)


• Look at me! (NOT look me)