your mistake is with 'lo ' i think. 'lo' in this sentence is substituding a quality. Try to translate 'voy a asumir que es rojo' 'i an going to asume that it is red', In this sentence 'lo' is a copulative complement is not a pronoun, it is a bit confusing, i know, if you need more details, please let me know.
I'm a native speaker, and "I'm going to assume that is it" actually is a valid thing to say in English. "I assume that she did it" and "I assume she did it" both work, so it's also fine to say "I assume that is it" the same way you could say "I assume that that is it," if "that is it" is what you're assuming. It doesn't work as a translation of the Spanish sentence given, though.
Hey guys, this translation is wrong. The Spanish equivalent for it would be "Voy a asumir que si" (the final i with an accent, which I don't have on my keyboard). It would be a perfect answer to "Is it bla-bla-bla...?" type of question. IMHO, the correct translation of the given Spanish sentence is "I am going to assume that it is so" (or "... that it is like that"). Unfortunately it was marked wrong. The difference is that by saying the sentence I do not necessarily agree with someone, but I might be confirming some idea I previously expressed.
In English "that is it" is mostly used idiomatically to mean (1) "job done' or (2) "exactly". The Spanish phrases "lo es" and "eso lo es", as far as know, don't have such meanings, or, at least, the first one (native speakers of Spanish, please correct me if I am wrong). My understanding is that "Voy a asumir que lo es" means "I'm going to assume that that's the case"
I don't understand this sentence neither in English, nor in Spanish. Can anyone explain to me what it means? For me 'to assume' followed by a subordinate clause means 'to take as a true statement', but this meaning does not fit in here. "I'm going to find out what it is" and "I'm going to accept it no matter what it is" both make sense to me, but Ian Comyns' sentence doesn't.
Because the phrase is spoken and it's not possible to tell whether there is an accent on "que" it seems to me that assuming that there is an accent is reasonable and the translation would be "I am going to assume what what is." ( as in "I don't know what it is, but I am going to assume what it is") Does this make sense?
While that may be the case, the primary translation of asumir is "to assume" (or any of its related forms). The translation "to accept" comes much further down the list and is used in a limited sense of its general meaning of acceptance.
See http://www.spanishdict.com/translate/asumir for a sample of the specific case I described above.