Translation:You cannot pay yet.
Why is it "you"? There is no あなた or anything indicating that "you" cannot pay. Why is "I can not pay yet" accepted.
"まだお金をはらってはいけません。 " is in the imperative mood, which requires a second-person subject (you) in English. So even though it doesn't explicitly say "you", it's implied.
It has to do with the sentence pattern of ~てはいけません, which expresses a prohibition of sorts. You use this to say something to the effect of "this is not allowed", like you are stating a rule.
Thing is, "cannot pay" and "can not pay" are two different things. One means you mustn't pay, the other means it's okay not to :S technically only cannot should be accepted here.
"Can not", "cannot", and "can't" are all the same. M-W simply defines "cannot" as "can not" (https://www.merriam-webster.com/dictionary/cannot), and the same goes for "can't" (https://www.merriam-webster.com/dictionary/can't). The OED says "cannot" is preferred over "can not", unless the "not" part is part of another construction (https://en.oxforddictionaries.com/usage/cannot-or-can-not).
For example, "a pedant can not only be annoying, but also be wrong."
In American usage, if I say "you can not pay", I mean that it's okay for you to not pay. When you break up the word like that, the not is actually part of "not pay" rather than "can not". That's what Ichigotchi was referring to.
I think you may be taking past each other.
Phillip did not ask about cannot versus can not. I agree that the placement of "yet" in the English doesn't change the meaning.
But I also agree with Ichigotchi that "cannot" and "can not" mean different things. I think the Japanese means "cannot." But Duolingo is correcting me with "You can not pay yet," which seems technically wrong. It should be "cannot."
(This is probably not why it corrected me: I said "I" not "you.")
Update: "You cannot pay yet" is correctly accepted.
But couldn't it also be "I"?
I tried both "I am not allowed to pay yet" and "you're not allowed to pay yet" and both were rejected.
Duo accepted "you cannot pay yet" yet it said that I missed a space..... can_not
The form here expresses prohibition, as in "it is not ok to pay". It generally is used only when speaking to others and not about yourself.
You might want to check your pedantry at the door. "can not pay" has dual meanings, not only the one you are suggesting. One of the meanings is the same as "cannot pay", the other is as you suggested.
The link given above by IsolaCiao about breaking up the word reinforces that point (inadvertently).
I'm pretty sure "I can't pay yet" should be a valid answer, since there's no explicit subject. Still, it didn't accept it :/
"I can't pay yet" is incorrect because "まだお金をはらってはいけません。 " is in the imperative mood, which requires a second-person subject (you) in English.
I don't know. The "お金" is in the sentence (along with pay), so "pay your money" or "pay the money" would seem reasonable to me. Maybe it is a colloquial thing.
If 'ikemasen' implies a prohibition, then "you mustn't pay yet" is right. Why does it get marked as wrong?
Query: まだお金を払えません。You can't pay yet. まだお金を払うことができません。You cannot pay yet. まだお金を払っちゃいけません。Do not pay yet. まだお金を払ってはいけません。You must not pay yet. Is Duolingo confused between these distinctions?
This sentence means You don't pay the money yet. You can not pay yet. means あなたはまだお金をはらうことができません。
I think this particular sentense is situation specific. In Japan, there isn't a custom to leave money on the counter or table to pay. Monetary transaction happens either when purchase is made(fast-food places, for instance) or in the end, after eating/drinking and one is leaving. Also important to note, we do not leave tip on the table, it isn't a tipping culture. As a native Japanese, this sentence makes me think of a situation where I am with someone who is foreign to the practice and taking money out to leave on the table and I am telling him/her not to.
Including お金 implies or leaves room to question if you can pay by other means like credit or debit