Use of Hasta Que
Why does "hasta que" sometimes have a "no" after it , even though the dependent clause isn't negative?
3 Answers By Expert Tutors

Jose Enrique M. answered 08/10/21
Professional, passionate and dedicated . Making Spanish easy to learn.
The Spanish preposition hasta (ahs-tah) can mean either until or to, depending on the context of a sentence. Although still considered a common Spanish preposition, hasta only shows two things. That leaves you with a lot less to memorize in order to use hasta accurately.
hasta can only be used to show the following :
- Place/location: For example, to tell someone to Drive to the traffic light in Spanish, you’d say Conduzca hasta el semáforo (kohn-doos-kah ahs-tah ehl seh-mah-foh-roh).
- Time: If you want to say to a friend See you later or Until then in Spanish, you’d say Hasta luego (ahs-tah looeh-goh). At the end of a work day, you might tell a coworker Hasta mañana (ahs-tah mah-nyah-nah), which means Until tomorrow.
I agree with this expert.
I would add that the equivalent of "hasta que" in English is "until" :
Comeré hasta que no tenga hambre. (I will eat until I am not hungry).
Escribiré hasta que me canse

Leslie J. answered 01/21/21
Experienced and Patient Spanish Teacher able to tutor all levels
Using a "no" after hasta que is a colloquial use. It needs to be used when one uses subjunctive but not when you use indicative.
For example:
Trabajé hasta que dejó de llover.
No quiso caminar hasta que no dejara de llover.
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Hugo H.
The subjunctive is not the main issue here. There are two different meanings of “hasta que”. We have (1) one that indicates the end of an action, and (2) another one that indicates the beginning of an action. Let’s see these two examples: Subió las escaleras hasta que no pudo seguir más (S/he climbed the stairs until s/he couldn't go any further.). No subió las escaleras hasta que no logró juntar fuerzas, (S/he didn't climb the stairs until s/he managed to gather his/her strength). In the first sentence, “hasta que” indicates the end of the action “subir las escaleras”: S/he climbed the stairs, but s/he did it until s/he had no strengths to continue. (the “no” here has a real negative value). In the second one, “hasta que” indicates the beginning of the action “subir las escaleras”, Firstly, s/he gathered his/her strength and THEN AND ONLY THEN climbed the stairs. The second “no” is “triggered” by the first “no” in the main sentence, and it doesn’t have a negative value, but an emphatic one. That’s why we usually say that the second “no” is unnecessary, and is used mainly for emphasis. It is a colloquial use and we can delete it without affecting the meaning: “NO subió las escaleras hasta que logró juntar fuerzas” (meaning: (1) first gathered his/her strength and THEN (2) climbed the stairs). In this case, some linguists say that “hasta que no” could be replaced by “mientras no”. We understand that both sentences would have a similar meaning (or the difference is so subtle that the speakers do not notice the difference): “No subió las escaleras hasta que no logó juntar fuerzas” and “No subió las escaleras mientras no logró juntar fuerzas”. The explanation for this is that “hasta” is the only preposition that comes from Arabic and in that language the preposition had those two meanings: hasta and mientras (until and while). In the first sentence, however, the “no” after “hasta que” is not for emphasis. It has not been triggered by a “no” in the main sentence (in fact, we don’t have a “no” in the main sentence). The "no" in the time clause has a negative value by itself, instead of being “emphatic”. The action of “climbing the stairs” takes place until the moment he doesn’t have enough strengths to continue. That “hasta que” marks the end of the action. In grammatical terms this “hasta que” is defined as “un hasta que durativo”. When the “hasta que” indicates the beginning of the action is defined as “un hasta que puntual”. But the name is not important. I hope this clarifies your doubts. Regards,02/11/22