I am about to go to a place where I will be expected to speak English. So,...

I am learning English because I will need it when I go abroad.

I go abroad to work often. My English is passable but could be better. So, ...

I am learning English because I need it when I go abroad.

They are both correct. It depends on what you want to say.

I am about to go to a place where I will be expected to speak English. So,...

I am learning English because I will need it when I go abroad.

I go abroad to work often. My English is passable but could be better. So, ...

I am learning English because I need it when I go abroad.