Like : We use it when the second term of the comparison is a noun, a gerund or a pronoun. Dave looks like his father. - Don't act like me ! To learn english is like having your own private tutor. Like can be modified with adverbs , such as : just, more, very much, not at all... : Just like you, Jane wanted to be a doctor. AS : We use it when the second term of the comparison is a verb, a clause or a preposition. Don't do as I do ! It started raining, as I said it would. Prices are very high, as in the 1990s. (as they were) As can be used before a noun: She works as a nurse.
Be careful :
She speaks like a teacher ...she is not a teacher. She speaks as a teacher ...she is a teacher.
In addition :
We can use like (or such as) when giving examples: He prefers classical composers, like Chopin. She prefers French actors, such as Delon. Some other constructions : We use like + noun or pronoun
as if/ as though + clauses
with some verbs: feel,look,sound,smell,seem,treat It looks like rain / It feels like rain. It looks as if it's going to rain. It feels as if it were going to rain. It looks as though it were going to rain. It feels as though it were going to