# Are there any seemingly opposites (e.g. negation) in Spanish which, in fact, mean something different?

To illustrate what I'm referring to, I'd like to give to examples in English:

While must not seems to be the opposite of must, it has a different meaning. Must go to school, for example, means I have to go to school, while must not go to school indicates that I am not allowed.

Another similar negation which is not truly the opposite is about to and not about to. When I say I'm about to leave I am gonna do soon. But saying I'm not about to means they I definitely won't do it. So, it's not quite the opposite.

If someone is not aware of these differences, he certainly will use them incorrectly.

Q: I wonder if there are similar examples in Spanish, which language learners will run into if they don't know.

• Well, "No tienes que quedarte a dormir" means "Tienes que quedarte a dormir" :) But I don't know if that is intrinsic to Spanish. – c.p. Jan 4 '14 at 13:39
• So, more seriously, I guess you are looking for non-idiomatic expressions. Also without sarcasm, since otherwise the list would be practically infinite. Is the question equivalent to "when does verb+no lead to a meaning different from the negation of the verb?"? – c.p. Jan 4 '14 at 13:40
• @c.p. ¿En qué contexto "No tienes que quedarte a dormir" significa "Tienes que quedarte a dormir"? Para mí este no sería un ejemplo de lo que se menciona en la pregunta. – lorddarkangel Jan 4 '14 at 17:51
• @lorddarkangel Bueno, por eso no contesté la pregunta. El contexto es "No tienes que quedarte a dormir, puedes ir con tus amigos a tomar cerveza" Significa lo contrario :D – c.p. Jan 4 '14 at 18:25
• @lorddarkangel Alguna gente piensa que los españoles suelen ser un poco hipócrita y te piden cosas esperando que hagas lo contrario: "No, para nada molestáis, quedaos un poco más". De ahí la broma. – Flamma Jan 8 '14 at 18:45