"How do you know what to say yes to"

What is this strange little phrase? I know what it means but how to understand it grammatically?

  • 3
    It doesn't seem any more strange than "How do you know what to do?" In this case, the "doing" is "saying yes to [something]"
    – Mick
    Nov 28, 2016 at 16:05
  • What makes it seem strange to you? Would you explain a bit more which part is causing you trouble?
    – ColleenV
    Nov 28, 2016 at 18:21
  • No exactly the trouble but the inversed 'what to' instead of 'to what'. How do I know to what I must say yes? Nov 28, 2016 at 19:08
  • 1
    You wouldn't say "To the question say yes"; generally, you would say "Say yes to the question." That's why the original sentence is structured in that order. "How do I know to what I must say yes" is a totally understandable sentence, but it sounds very archaic, and people might look at you weird if you spoke like that. Nov 28, 2016 at 19:23
  • People often think I'm weird, well English isn't my native language. Nov 28, 2016 at 21:40

2 Answers 2


"How do you know what to say yes to?"

follows exactly the same grammatical pattern as

"How do you know what to do?"

The clause "How do you know ___" requires a noun-like complement, or a relative clause. For instance, "How do you know Bob?" or "How do you know that Bob plays piano?"

In English, wh- clauses can serve as nouns. For instance "I have what it takes" (I have the necessary skills, strength, courage, attitude or whatever the situation requires) isn't so different from "I have five dollars in my pocket". The "what it takes" part, a wh- clause, works with "to have" as if it were a noun phrase.

The wh- clause "what to say yes to" thus serves as a noun which denotes something to which someone says, "yes": a metaphor for making a choice or accepting an alternative from among several. Being an wh- clause, it conveys the idea that this something is an unknown which needs to be determined.

"How do you know {wh- clause}" means "how do you determine the identity of whatever the {wh- clause} is interrogating about?" Or possibly "how did you obtain the knowledge of knowing the answer to {wh- clause}"?

"How do you know what time it is?" means "how do you determine the current time?" ("I look at my smartphone, these days"). The sentence could also mean, "How in the world are you able tell me what time it is, without looking at a clock?" ("I did look at a clock about 45 minutes ago and have a keen sense for the passage of time.") There is some ambiguity which depends on context, and on what "you" means: is it the "rhetorical you" which means "one", "someone" or "anyone"? Or is it simply the second person in the conversation.

"How do you know when to sell a stock?" means "how do you determine the timing for selling a stock?" ("I peer into my magic crystal ball.")

So "How do you know what to say 'yes' to" just means "How do you determine, from among these choices, the one to which you will accept by saying 'Yes'?"

It could be asking a specific person about what is their own approach to making the decision, or it could be asking in for advice: what is a good way to make the decision.


we native speakers do not worry about grammatical formalities. we (or at least i) can understand your example by reference to things like "he said yes to that question". so you can gloss your example as e.g. " how do you know when to say yes?" or "how do you you know which questions should be answered by 'yes'?"

ps. it's not strange, in and of itself. I can imagine many situations in which it would be completely normal; for example, an interrogation.

fwiw, there's an old, bogus rule in (American) English that says " never end a sentence with a preposition." a joke: instead of "that is something I will not put up with!" (which is 100% natural), we are to say instead "that is something up with which I will not put!", which is just ridiculous.

another joke:

visitor: "where's the Harvard Library at?"

harvard man: at Harvard we do not end our sentences with prepositions.

visitor: ok. Where's the Harvard Library at, asshole?

  • Yeh, the rule doesn't work. Dec 1, 2016 at 7:27

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .