How to use "whether" in Chinese - do you need to say 如果？

Question

I've always had a bit of difficulty with statements with the term "whether" in Chinese. In this sentence I would like to say "I asked him whether or not he had met Mark." - I translated this in my diary as "只有我跟一个卢旺达人讲了一下 如果他认识不认识Mark Should I use 如果 in this instance? In english there is a murky divide between "Whether" and "if" but I'm not sure if this exists in Chinese.

Answer 1

I would offer the same sentence as Zezi's -- 我问他认不认识马克。There is another somewhat less colloquial way: 我问他是否认识马克。如果 is entirely out of place here. 如果 means in case -- not whether.

Answer 2

the sentence should be: 我问他认不认识马克。Whether/if or not does not always translated as 如果 in the sentence. 认不认识 already shows the question.