Q1: I learnt "last year" and "in the last year" are very different in meaning. In my understanding, "last year" seems to be a indivisible time frame when it is used in past simple. For example, today is 2017-03-03 and if I say:
I went to Mexico last year.
Does that mean "I went to Mexico at 2016-03-03"?
In contrast, "in the last year" seems to be used in present perfect only. And if I say:
I have been to Mexico in the last year.
Does that mean "I have been to Mexico at least once in last 365 days"?
Please correct me, it would be better if you can tell more about how to understand the direct and indirect meaning of these two phases because they are same if literally translated to my mother language.
Q2: I also heard "this week" can be used in present perfect. Is that correct? The present perfect seems to describe an action happened at an unspecified time before now. How to understand the meaning of "this week" if it could be used in present perfect?
Thanks for the help!
Best Answer
in the last year means "in the last twelve months (or so) including today".
If you were outside the country as recently as this morning, the questioner would expect you to answer "yes", even if your trip this morning was the only time you had been outside the country.
Since in the last year impinges on the present, the present perfect is fully grammatical.
It is equivalent to "Counting backwards from today..."
last year = during the previous calendar year (e.g. 2017 -> 2016).