Know a person

[Crack1]

1] Nous nous connaissons depuis longtemps.

2] Je vous connais depuis longtemps.

How about my French sentences?

We know each other for a long time.

I know you for a long time.

[Cedrick]

Your French sentences are perfect.
but it seems to me that in English it should be:
We have known each other for a long time.

I have known you for a long time.

[Crack1]

Yes, Cedrick
I have made a blunder.
It should be 'We have known each other for a long time' and ' I have known you for a long time'.

The present perfect is the correct English tense in this context.
Sometimes I make stupid mistakes.