Learn Arabic (Modern Standard): متى يبدأ الاجتماع غدا؟

No, Arabic doesn't use helping verbs like 'do' or 'does' for questions. You simply put the question word متى at the start, followed immediately by the main verb يبدأ (begins) and then the subject الاجتماع (the meeting).

Why does the verb يبدأ start with a 'ya' (يـ) if it is about a meeting?

The prefix 'ya' (يـ) makes the verb masculine, like saying 'he begins'. In Arabic, all nouns have a gender, and الاجتماع (the meeting) is masculine. Therefore, the verb must match it by taking the masculine form يبدأ.

Since the meeting is tomorrow (غدا), shouldn't the verb be in the future tense?

You could use the future tense marker 'sa-' (سـ) attached to the verb, but you don't have to! Just like in English where we can say 'The meeting begins tomorrow', Arabic often uses the regular present tense يبدأ for scheduled events in the future. The word غدا (tomorrow) provides all the future context you need.

Why is there an Alif (ا) at the end of غدا (tomorrow)?

That Alif carries a special 'an' ending sound called tanween, making the word 'ghadan'. In Arabic, time words used as adverbs to answer 'when' something happens usually take this 'an' ending, which is why it's written as غدا instead of just 'ghad'.