Back in the Cretaceous when there used to be cigarette advertisements on TV, there was a commercial that claimed:
“Winston tastes good like a cigarette should.”
Well, the English teachers, librarians, and grammarians of the day all had a mass conniption, because it should have been:
“Winston tastes good as a cigarette should.”
Soon afterward, Winston came out with a new commercial:
“What do you want, good grammar or good taste?”
I don’t know if that ad was done by the same advertising agency as the first commercial or not. But I do know that misusing “like” and “as” is considered a cardinal sin in grammar circles; therefore, I’m going to make sure that you don’t commit this error.
“Like” is a preposition that takes an object, either a noun or pronoun.
He plays golf like a pro. She sings like a canary.
“As” is a conjunction connecting two phrases, each of which includes a verb.
In the Winston example, you have the phrase “Winston tastes good” being connected with the phrase “a cigarette should.” Both have subjects and verbs. Therefore, the ad agency should have used “as” in the original commercial. They got quite a black eye; and because they would rather fight than switch, they would have done better in a Lucky Strike commercial!