Today we’re going through the question words, as the title suggests.
Who = مَن (man); “Who is it?” = مَن هُوَ؟ (man huwa).
What = ما (mā); “What is it?” = ما هُوَ؟ (mā huwa). Note that this is Modern Standard Arabic. I can’t speak to colloquial Arabic except in my limited personal experience, so I can say that you’ll encounter شو (shū) instead of mā, heavily in Lebanon but also frequently in other places.
Where = أينَ (ayna); “Where is it?” = أينَ هُوَ؟ (ayna huwa).
When = مَتى (matá) or عِندَما (ʿindamā); “When are you going?” = مَتى تَذْهَب؟ (matá tadhhab).
Why = لِماذا (limādhā); “Why are you going?” = لِماذا تَذْهَب؟ (limādhā tadhhab).
How = كَيف (kayf); “How are you?” = كَيف حالُكُم (kayf hālukum).