Translation:It is not good to speak with your mouth full.
I disagree. When referring to body parts in Spanish, the definite article (el, la) is often used instead of the possessive pronoun (his, her, your). It is important to look at the context of the sentence to see which one makes sense. In some cases, when there is ambiguity, I think both should be accepted, but in this case I think the context is fairly clear.
I translated this as "It's not good to talk with THE full mouth" which was marked wrong...saying it should be "It's not good to talk with A full mouth". I understand that is the more common phrase but the sentence given used the article LA, not the indefinite UNA...so why was I marked wrong?
I agree - it's certainly more common to use an indefinite article in this situation but DL specifically used the definite "la", which is why I translated it as such. I reported it because I have been marked wrong too many time when I put in "a" or "an" and they wanted "the"! Can't have it both ways!
I think it just comes down to translating the sentiment instead of the literal. In this case the best translation is probably "your mouth full" because Spanish will often use the definite article instead of a possessive when referring to body parts. "The mouth full" conveys the same sentiment, in a general way, and should also be accepted, but "the full mouth" sounds, oddly enough, like a Spanish person trying to say this in English :) In comparison, "a full mouth" conveys the same sentiment as "the mouth full" which is why it would be accepted, even though the indefinite article usage is not a literal translation.
That's a literal translation from the Spanish, but it only works in a very specific and obscure context in English. Here are the possible translations in descending order of likelihood:
It's not good to speak with your mouth full - The Spanish definite article is normally used instead of possessives when referring to body parts, so "la" translates as "your".
It's not good to speak with a full mouth - This is just a general variation of the above.
It's not good to speak with the mouth full - Another general variation of the first translation, but a far less common / more formal one.
It’s not good to speak with the full mouth - Literal, and possible, translation, but it would require a highly unlikely context where "the full mouth" is an entity with whom it is not good to talk. As in: No es bueno hablar con la televisión - It's not good to speak with the television.