Translation:I spoke to you about my trip last year.
I think the "spoke with" rather than "spoke to" part makes sense, but "my last year's trip" sounds incredibly wrong. I think it's because "my last year" didn't take the trip..."last year's trip" is fine, if you're not specifying whose trip it is, but "my last year's trip" isn't a valid English phrase, it really has to be "my trip last year", or something like "the trip I took last year" if you want to avoid the temporal ambiguity that happens in the English translation (did we speak last year about my current/future trip, or did we speak at some point about my trip last year?).
Literally, the Spanish sentence means "I spoke to you about my trip of last year." This is an accurate and unambiguous translation. It's clear that "last year" describes the trip, not when the person spoke. However, a more natural English translation is Duolingo's "I spoke to you about my trip last year." Technically, this introduces an ambiguity about whether "last year" describes the trip or the speaking. However, native English-speakers will assume (correctly) that "last year" refers to the trip. They will make this assumption, probably without even thinking about it, because "last year" immediately follows "my trip." If a native English-speaker meant that the speaking occurred last year, they would say instead: "I spoke to you last year about my trip." In short, Duolingo's featured English translation is better because it's perfectly natural and conveys the same information.
"Told" is more common, but is it a faithful translation of the Spanish?
"I spoke to you about..." sounds like the speaker mentioned only a few things about the trip. "I told you about..." suggests a fuller account. It doesn't matter that "told" is more common, if it misrepresents what the Spanish sentence says.
Jeff, you hit the nail on the head. Instead of trying to an appropriate English translation, we should be focusing on what the Spanish is trying to convey. The key here is the use of del vs. el. By using del, it conveys that the trip happened last year (of last year). If el were used, it would be that it was last year when you spoke about the trip.
I just love this! On the French studies commentary wall, people are pulling their hair in frustration of the next-to-impossible-to-learn language. Here people are mostly commenting on the English translations :-D
Conclusion: In comparison, French is very, very hard to get. Spanish is quite ok. :-)
An English speaker would much more likely say: "I spoke to you about my trip OF last year" or "I spoke to you about my last year's trip" rather than the translation above. One just wouldn't say "my trip FROM last year". The trip didn't come from the past year, it occurred last year, hence the use of the word "of".
You're partly right, however, your examples are not. "I spoke to you about my trip of last year" is equally bizarre.
The most common ways to convey the thought are:
"I spoke to you about last year's trip". (Possessives are the most common way to express an occurrence within a timeframe. See also "last Tuesday's meeting" or " Next month's schedule". )
"I spoke to you about my trip last year" (In the abstract, it's unclear whether the speaker did the speaking last year, or ABOUT the trip that TOOK PLACE last year, but this is almost always clear from context, and an extremely common way to convey the thought.)
Duolingo's featured translation is fine. There's nothing to report. The Spanish sentence means "I spoke to you about my trip of last year," (which is technically correct but sounds unnatural), and Duolingo's featured translation "I spoke to you about my trip last year." conveys this information to a native English-speaker in natural English. The technically possible ambiguity won't be noticed in normal conversation.
'mi viaje del ano pasado" means literally "my trip of last year, or "last year's trip". For the above to mean I spoke to you about it last year, I think it should be "Yo te hable sobre mi viaje el ano pasado" or "Yo te hable el ano pasado, sobre mi viaje", No? (no Spanish keyboard, so accents, etc.missing)
"Last year's trip" is possessive, not a contraction.