Student or Learner
First, Ask and request have the same meaning, but request is more formal and more polite.
Does these sentences sound natural?
I ask my father to give me his car today. I asked my father for the car.
I requested the car from my father. We requested old books form potential donors.
I just cannot use my vocabulary very well. Would anyone tell me the best way to tackle this problem?
I wish I had better English, but I work hard to improve it. I'm studying for IGCSE, so I'm only interested in BrE.
"Request" and "ask for" have the same meaning. I would not say that "request" and "ask" have the same meaning.
I requested a piece of paper.
I asked for a piece of paper.
I asked a piece of paper.
I asked my father a question.
I asked a question of my father. (though a little uncommon)
I requested a question of my father.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.