How do you use "become" or "have become" when this verb is so vague about time?
I'm not sure what tense to use here.

For example. I am friends with Allison. Now she and I become boyfriend girlfriend.

Can I use "have become" also? Because being boyfriend girlfriend started in the past up until now.

Can anyone explain to me how I can distinguish when to use "become" or "have/has become"?

Thanks in advance.

Question

How do you use "become" or "have become" when this verb is so vague about time?
I'm not sure what tense to use here.

For example. I am friends with Allison. Now she and I become boyfriend girlfriend.

Can I use "have become" also? Because being boyfriend girlfriend started in the past up until now.

Can anyone explain to me how I can distinguish when to use "become" or "have/has become"?

Thanks in advance.

Answer

"She and I have become boyfriend and girlfriend" is grammatically correct- "we become" is wrong in this context. And your explanation is exactly right- started in the past and is still true now.
(But it would sound much more natural to say something like "We've started going out" )

The difference between "become" and "has/have become" is the same as the difference between any instance of the present simple and the present perfect.
"when you freeze water it becomes ice"
"I've put the water in the freezer but it hasn't become ice yet"

I hope that helps

Answer

'we have become..'  is correct but not really natural.
'we are now..'  is the most common way.
:)