Why is it wrong?

They’re both correct, just used in different situations. “Won’t” means the theater opening is something yet to happen. “Wouldn’t” means you’re talking about some time in the past and 7:15 PM has passed. There’s no way to tell which is correct in the context of this question, since all you get is this sentence.

It isn't wrong.

Because it’s reported speech. Google that

Context-dependent: if they told you this being true in the past, you’d use wouldn’t. If it was going on in the present or future it would be won’t

I think it's because of tense. They said "told" and you answered with "won't". "Won't" sound more present tense to me. I think "wouldn't " matches the past tense of "told" more.

I'm sorry you're getting a lot of mixed responses OP. The problem is that a lot of native speakers have forgotten what reported speech is and when asked, focus on when the event is happening. Not that the info on the event was provided in the past. It's the same for stuff like "I thought you had a wedding next year" Natives will assume it's "you have/will have" because it's about next year. But those same natives will without thinking say stuff like "I thought you wanted to go to Disneyland today" without noticing the use of past tense twice (even though it's not the past). I think you have a wedding next year (as far as I'm concerned) I think you will have a wedding next year (prediction) I thought you had a wedding next year (I was sure you had one coming, but I've just received contrary info). \>>>Notice "I was sure you had"​, not have/will have. <<<

I think a lot of people are missing the most obvious. “Told” is past tense, while “won’t” is future tense. “Wouldn’t” is also past tense, so is the correct option with no other context. If we keep the entire sentence as past tense, that’s following the context. If we change the tense to future tense, we’re adding additional information (that we are before 7:15pm) that isn’t in the sentence already. In general, I was always taught to avoid switching between past/present/future tense unless it was needed in the situation. So if it’s not needed in the sentence, keep it all one tense.

"Wouldn't" is correct. This is reported speech with backshifting. Original statement was: "The theatre won't open until 7:15." In reported speech after "They told us" (past tense), you backshift "won't" to "wouldn't." Basic grammar rule - future forms shift backward when reporting past statements. Easy \^.\^

The conditional ("would") is used when talking about the past's future, i.e., the future from the perspective of the past.

Tbh as a native speaker I'd use them interchangeably

I think you may find this useful! https://www.ef.co.uk/english-resources/english-grammar/tense-changes-when-using-reported-speech/

To me it seems as if they are talking about the future so I would think won’t is correct. That’s how I would say it. Doesn’t mean it’s right though.

It’s future in the past. The person said: “the theatre won’t open …” When you report what they said (verb ‘tell’) you need to backshift ‘will’ to ‘would’.

They _told_ us (in the past) that the theatre _wouldn't_ open (also in the past) ... However in real, day-to-day speech, your answer is also acceptable.

Don’t speak freely. Reddit bans free speech.

"Wouldn't" would work if it was used in something like: A: "What if we first went to the movies at 6:30, and then had dinner?" B: "They told us the theatre wouldn't be open until 7:15pm." Here it works because it's a hypothetical situation.

Reported speech

Both sound fine to my ears, but yes, the grammatically correct option is a, as people explained.

Wouldn’t is past tense and would is current to me they’re both fine just sounds like a bad quiz/teacher

(I’m not an English teacher or linguist, so take this with a grain of salt) Wouldn’t is a contraction of ‘would not’ Won’t is a contraction of ‘will not’ Would is past tense, Will is future tense The confusion here comes from the fact that you are not directly quoting the person, you are simply restating the information they conveyed to you. In all likelihood the person did in fact say “The theatre won’t open until 7:15pm.” And if you were quoting them you’d say “They told us ‘The theatre won’t open until 7:15pm.’” However, I think it is wrong to mark ‘won’t’ as incorrect, as it really depends on when you are talking. If you said this after 7:15pm the opening of the theatre is now in the past and it would be correct to use ‘wouldn’t’, but if you said it before 7:15 then the opening of the theatre would still be in the future and you could use either ‘wouldn’t’ or ‘won’t’. This is a tricky one so I can see why non-native speakers would struggle with it. I’m struggling to make sense of it for the opposite reason; It’s so natural to me that I’ve never even thought about it.

I think you are correct. If the correct answer is "a. Wouldn't" then it should've been followed by "be" afterwards, right?

"The theatre won't open until 7:15pm" "They told us the theatre wouldn't open until 7:15pm" The 1st, is someone "in the present" talking about the future. The 2nd, is someone "in the past" talking about later events. That rule generally holds true. Eg. "I promise I'll go to the gym every day" / "I promised I would go to the gym every day". (just to add - even some native English speakers might use the future tense - "won't" - there. But I don't think it's correct)

Tbh this seems really nitpicky. "Wouldn't" is more of a hypothetical prediction, "won't" is more definite. I may be wrong but I think this is subjunctive mood, which to be frank, is often not used "correctly" by native speakers. You could totally say "won't" in this example and no one would really notice. That's not to say "won't" and "Wouldn't" are interchangeable, but in this example there isn't much meaning. Without additional context, I can't actually say "won't" is wrong.

Won't is the junction of will not, and to use will not you need a 'to be' verb after, like, will not be open or won't be open. As you don't have a 'to be' verb, the correct answer is wouldn't, or would not. I can't remeber about the names of the different times in the past from my English lessons (I'm not a native English speaker BTW), but is more or less this Edit: I think it's something related to reported speech