a question about "never"
 

I am going to make up three sentences with "never".

(1) I never traveled to Mexico. (simple past)

(2) I never travel to Mexico. (simple present)

(3) I have never traveled to Mexico. (present perfect)

"never" means not at any time. If something never happened, it didn't happen at any time.

How does each tense change the meaning of the sentences? Please explain this. Thanks a lot.

Re: a question about "never"
 

As always, you can't understand them without context.

1) simple past - talking about past events when, generally, the time reference is explicit.
Between 1980 and 1983 I took time off and travelled all round the world. I went to 200 different countries. The only one I missed - and I really regret it, was Mexico. I never travelled to Mexico and I would like to have seen it.


2) Present perfect - talking about past events when the exact time reference is indefinite - we know it happened before now, but not when.
A : I hear you've spent a lot of time in Mexico?
B: Who told you that? I've never travelled to Mexico.


3) Present simple - talking about "permanent " events - true in the past, present and potentially the future (eg I live in Italy - that was true yesterday, is true today and will be true tomorrow)
I work for a company that does a lot of business in central America, so I go there a lot. Panama, Nicaragua, Costa Rica,... They do a lot of work in Mexico too, but for some reason they never send me there. I never travel to Mexico.

My only other comment would be that the use of the verb go is more common than that of travel. So in these examples I'd prefer :
a) I never went to Mexico
b) I've never been to Mexico
c) I never go to Mexico.