Learn Arabic (Modern Standard): هل الكلب يشرب الماء؟

In the present tense, we add prefixes to the verb to show who is doing the action. The prefix يـ (ya-) at the start of يشرب tells us the subject is a masculine "he" or "it". If the subject were feminine, the verb would start with تـ (ta-).

Does Arabic have a different verb form for "is drinking" versus "drinks"?

No, Modern Standard Arabic uses the same present tense verb for both. يشرب can mean "drinks" as a general habit or "is drinking" right now. You just pick the English translation that makes the most sense.

I learned that Arabic sentences often start with the verb. Why does الكلب come before the verb here?

You are right that verb-first sentences are very common. However, subject-verb order is also completely correct and frequently used in Arabic. Placing the noun الكلب right after the question word هل is a very natural way to ask about a specific subject.

Can I translate هل as "Does" in this sentence?

Yes, in this context it translates perfectly to "Does". However, هل is simply a question particle used to turn any statement into a yes/no question. It doesn't mean "does" or "is" on its own, but rather acts like a spoken question mark at the beginning of the sentence.