Improve your English : As or Like?

  AS or LIKE?

If there is no verb, just a noun , you will use a preposition.

 Use like for the meaning similar to, and use as to refer to the role of a person or thing.

Compare these examples:
You look like your sister. (You look similar to your sister.) It is a comparison.
  (like ici = comme) 

As your sister, I’d like to give you some advice. (This might be said by a woman speaking to her brother; she is his sister, so as, not like, is correct.)
   (as ici = en tant que) 

You sound like a teacher! (This might be said to a student who is explaining a grammar point to another student. It only makes sense if the person referred to is not really a teacher.)

It’s up to her, as the teacher, to design the curriculum. (She is the teacher.)