Summary: It’s correct to use the question word what with the preposition like, but incorrect to use the question word how with the preposition like. So what it looks like is correct, but *how it looks like is incorrect. In grammatical terms, we need to use the noun what after the preposition like, not the adverb how.
First, take a look at this sentence and the question that follows. Think about whether the constructions are “grammatical” in Standard American English (SAE).
*I’ve heard of John Lennon, but I’ve never seen a picture of him. How does he look like?
If you thought there was something ungrammatical in the writing above, give yourself a pat on the back because you’re right. Here is how the above could be corrected:
I’ve heard of John Lennon, but I’ve never seen a picture of him. How does he look?
This is also correct:
I’ve heard of John Lennon, but I’ve never seen a picture of him. What does he look like?
But why? What’s wrong with the original question? Let’s take a closer look. And don’t worry. We’re going to do this the easy way, so if you run away from grammar terms like conjunctive adverb, you should be okay. Of course, if you have any questions, please post below, and I’ll do my best to help.
The easy explanation
I wrote out five different explanations of why this is wrong, and in the end, I think the easiest way to explain why “how does he look like” is wrong is to use the “move the words around” method, which actually works surprisingly well for a lot of grammar explanations. First, it’s important to wrap your head around the concept that many utterances (i.e., things you say or write) in English can be worded differently and still have more or less the same meaning (although different emphases will likely result). For example, I can ask “What were you writing with?” or “With what were you writing?”, and the two questions mean pretty much the same thing, although of course, the latter sounds more formal than the former. Let’s do the same thing with our above examples.
But we’ll need to shorten things a bit. Let’s just get rid of the opening sentence and focus on the question, i.e., the “what does he look like?” part. Now, let’s rearrange the words a bit, do some other magic, and write two equivalent clauses. Let’s start with the two correct examples:
“What does he look like?” can be rearranged thus: “He looks like… what?”
Similarly, “How does he look” can be reordered like this: “He looks… how?”
Finally, and this is the important one, following the same procedure, “*How does he look like?” would be reordered like this: “*He looks… like how?” Does that sound wrong to your ears? I hope so, because it sure does mine! When was the last time you heard someone say “like how”? We hear “like me”, “like you”, “like a movie”, etc., but not “like how”. Right?
For the same reasons, these are also wrong and need to be rewritten:
- Not good: *How does eggplant taste like? Better: What does eggplant taste like?
- Not good: *How does goose down feel like? Better: What does goose down feel like?
- Not good: *How does lavender smell like? Better: What does lavender smell like?
- Not good: *How does a foghorn sound like? Better: What does a foghorn sound like?
If you noticed that I used verbs for our senses, you get bonus points.
Curious about the grammar behind all of this? Read on.
But why? Give me the grammar!
Let’s take a look at the grammar. First, we need to understand that the word “like” is a preposition. Second, we need to know this very important grammar rule:
preposition + noun
Prepositions are words such as in, of, with, like, etc. After a preposition, we should have a noun. This noun is called the object of the preposition. For example, if we say “on the table”, “on” is the preposition, and “table” is the object of the preposition “on”. (For more information, see the TestMagic page on prepositions.)
Now hold onto your hats, as this is going to get a bit technical. (Hopefully it’ll all come together in a bit.) We have established that “like” is a preposition and it needs an object (which is a noun). That object is the word “what”. Why? Because “what” is a noun; “how” is not a noun (it’s an adverb). So, if we have “like” in this question, we can’t also have “how” in it; these two words don’t get along, and they can’t be in the same sentence or question together (in this construction, of course). We need to get rid of one or the other. So, we can say “what does he look like” and “how does he look”, but we can’t say “*how does he look like”. Simply put, we need preposition + noun, not preposition + adverb.
Need more detail? Here you go: When we ask a question and expect the answer to be a noun, we use the “question word” (also known as an “interrogative“, “interrogative word“, or “WH question word“) “what” (for things) or “who” or “whom” (for people) at the beginning of the question. For example, if we want to know what you ate for lunch (a thing), we could ask “What did you eat?” Similarly, if we want to know whom you saw, we could ask “Whom did you see?” (Don’t worry right now about the difference between “who” and “whom”; that’s a whole different subject!) And to wrap this up, since we’re using these words in questions and because they’re used to ask for nouns as answers, they’re called interrogative (“interrogative” basically means “asking”) pronouns (words that substitute, replace, or refer to nouns). In other words, they are question words that function as nouns. In other words, you use a noun in the question to get a noun as the answer.
In contrast, when we ask somebody “how” (followed by a clause), we want to know the way something happened, the qualities of something, etc. In other words, we’re looking for an answer that’s an adverb or an adjective. And yes, “how” is an interrogative adverb, if you were wondering.
So that’s it! Let me know if you’d like some clarifications or further explanations.