Confusion with As and Like

There is often quite a bit of confusion with As and Like, in one of their uses they both seem to mean ’similar’ or ‘the same’. I’ve written this with the intention of trying to make this a little clearer so that less mistakes will be made.

Both As and Like can be used as conjunctions and prepositions, whilst As is also sometimes an adverb and Like also a verb. Here’s an example of each:

As as an adverb – Alice is as intelligent as her brother.

As as a conjunction – As prices rise, so people find it more difficult to maintain their standard of living.

As as a preposition – As your manager, you are expected to do what I tell you.

Like as a verb – He didn’t like her very much.

Like as a conjunction – It looks like it’s going to be hot today. (informal – see below*)

Like as a preposition – John is like his father.

The confusion between these two words is when they are used as prepositions.

When used as a preposition, As usually expresses the meaning of the verb be,

As a manager he had certain responsibilities.

Whereas Like when used as a preposition usually means ’similar to’,

Dressed in his suit, he looked like a manager.

As

As a preposition As has two main uses

1. It expresses comparison  He behaved as cool as a cucumber.
   In this use, as comes before a noun phrase. As you can see, this is idiomatic; there are many other phrases that are similar in this way:
   as hard as nails as brave as a lion as white as snow

2. It also expresses the meaning of the verb be (this is where much of the confusion with like occurs):
   As a doctor, I have certain responsibilities. (= being a doctor)
   He acted as a guide and showed them the sights of the old city. (= his role/job in that situation was that of a guide)

Like

Like, when used as a preposition, means ’similar to’ (not ‘being’ as above). Like here is used as a comparison.

In many ways, London is like New York.

The mountains in the UK look nothing like the Alps.

So what’s the confusion, then?

Take the examples above and replace like for as, and as for like:

As a doctor, I have certain responsibilities. (= being a doctor)

Like a doctor, I have certain responsibilities. This makes sense, but the meaning is different. It doesn’t mean that the person speaking is a doctor but that they are acting in the way that a doctor would, in other words similar to.

He acted as a guide and showed them the sights of the old city. (= his role/job in that situation was that of a guide)

He acted like a guide and showed them the sights of the old city. In this case, the two are very similar, so the meaning here is almost the same.

In many ways, London is like New York.

In many ways, London is as New York. This makes no sense at all because London cannot ‘be’ New York, they are two different places. They can only be similar.

The mountains in the UK look nothing like the Alps.

The mountains in the UK look nothing as the Alps. The same is true here as above.

Have a look at these examples:

He’s a great swimmer, he swims like a fish. (NOT He swims as a fish. Because he is not a fish, he’s a person!)

Mother works like a slave. (NOT She works as a slave. Because she’s not a slave, she’s a mother!)

*And another thing…

Be careful when using like instead of as if. You can do this, but it is an informal usage.

It looks like it’s going to be sunny again.

It looks as if it’s going to be sunny again.

Here Like is being used as a conjunction (followed by a clause) not as a preposition (followed by a noun or noun phrase). It’s better, I think, to stick to it’s use as a preposition and be careful about using it as a conjunction, because many English speakers consider this to be incorrect.

In Summary

Like and As are often confused in their use as prepositions.

When used in this way, these are their meanings:

Like = ‘being’

As = ’similar to’

Confusion with As and Like.