Like vs As
Level B1 · Prepositions
like and as both compare things, but they answer different questions. like (a preposition) says two things resemble each other — X is similar to Y, but X isn't actually Y: She sings like an angel (she isn't an angel, but she sounds similar). as (usually a conjunction here, or a preposition meaning 'in the role of') says what something genuinely is or does: She works as a teacher (she genuinely is a teacher, not just similar to one).
Choose based on whether you're comparing (like) or stating a real role/function (as):
- like + noun/pronoun for resemblance: He looks like his father; It tastes like chicken; Nobody dances like her.
- as + noun for a genuine role, job, or function: She works as a doctor; I used the book as a doorstop; He was employed as a translator.
- as + subject + verb, to introduce a full clause (never like in this pattern in standard English): Do as I say (not do like I say); As I mentioned earlier, the meeting is cancelled.
- like can also mean 'for example', informally introducing examples: I enjoy sports like tennis and swimming (= such as).
The most common mistake is using like before a full clause with a verb — do like I say and nobody understands me like you do are common in casual speech but considered incorrect in standard/written English; the correct conjunction there is as: do as I say, nobody understands me as you do. A second frequent error: using as for a simple resemblance instead of like — he looks as his father is wrong; looks describes a resemblance, not a real role, so it needs like: he looks like his father.
Look for like directly before a noun or pronoun (resemblance) or before an example list, and as directly before a noun naming a genuine role/job, or before a full subject + verb clause — never like immediately followed by a subject and a verb.