in the past (year)

[neb090]

I didn't want to do a lot of typing. And I don't want to argue.

So "I visited many countries in the past year." is a correct sentence?

 

[5jj]

It's possible.

 

[emsr2d2]

1. I have visited many countries in the past.
2. I have visited many countries in the past years.
3. I visited many countries in the past.
4. I visited many countries in the past years.

Which sentence is grammatically correct and more idiomatic?

I see no need for any mention of the past if you're talking about the course of your entire life. The use of the present perfect suffices.
I've visited many countries.
If you're being more specific about the timescale, give the actual timescale:
I've visited many countries in the last ten years.

Because I read a the following sentence: and it says:

The major sporting events we have held in the past, including the World Games, have proven that we have the capability to hold such events.

You need to provide the source and author of that sentence.

About Regarding/With regard to 2, I read sentences such as:

1. That's why they have accomplished so little in the past few years.
2. Many workers have taken to the arts in the past few years.

(I have been taught that when using in/for/during/over the past/last years/days/months, I have to use the present perfect tense.)

You need to provide the source(s) and author(s) of those two sentences. Always number sentences when you give us more than one to look at. Remember to end every sentence with an appropriate punctuation mark.

Hi, 5jj.

I read this the following sentence in an article: and it say:

For the last year, Coughlin has been consorting with the enemies -- Sprint Corp., T-Mobile US Inc. and Verizon Communications Inc. -- to get the message across.

In this sentence, why doesn't the author add the number or few?

Source: by The Dallas Morning News, CheryI Hall, no slash here 2013 The Dallas Morning News.

Start every sentence with a capital letter. End every sentence with an appropriate punctuation mark.
If you need an em-dash, you can use two hyphens but make sure you put a space at either end. (On some keyboards, it's very difficult to make an em-dash so many of us make do with an en-dash, commonly called a hyphen.)

Could "In the past" could also be used with the perfect tense?

Work on your question construction (word order).

(I have been taught that when using in/for/during/over the past/last years/days/months, I have to use the present perfect tense.)

And since "in the past year" means "for the past 12 months", I doubt whether it is correct to use "visited" instead of "have visited."

Work on your use of articles. Remember closing punctuation.
Don't put a space after opening quotation marks.

Hi, Tarheel.

Again, note the correct use of capitalisation and punctuation.