As vs Like: Role, Similarity, or Clause?

Like usually compares similarity; as often identifies a real role, function, manner or clause relationship.

Like: similar to

Use like + noun/pronoun when one thing resembles another.

• She sings like a professional. (Her singing is similar to a professional’s.)
• This tastes like coffee.

As: in the role of

Use as when the noun describes the person’s or thing’s actual function.

• She works as a tutor. (Tutor is her role.)
• We used the box as a table. (That was its function.)

Compare: He spoke like a teacher means his style resembled a teacher’s. He spoke as a teacher means he spoke in his capacity as a teacher.

Before clauses

Traditional standard usage prefers as + subject + verb: Do it as I showed you. In informal speech, like I showed you is common, especially in American English, but as remains safer in formal writing.

As if and as though

Use these for appearance or imagined comparison: He talks as if he knows everything.

Quick practice

1. She works ___ an engineer.
2. He runs ___ an athlete.
3. Please organise it ___ we discussed.
4. It looks ___ it might rain.

Answers: as; like; as; as if/as though.

Decision rule: similarity → like; actual role/function or formal clause link → as.