Learn Arabic (Modern Standard): أهذه السيارة جديدة أم قديمة؟

The prefix أ (a-) is a question particle. Just like the word هل (hal), you attach it to the beginning of a sentence to turn it into a yes/no question or to ask for a choice.

Could I use هل (hal) instead of أ (a-) here?

You will sometimes see it, but when offering a choice using the word أم (or), it is grammatically required and much more natural in Modern Standard Arabic to use the أ prefix instead of هل.

Why is the word for "or" أم (am) instead of أو (aw)?

In Arabic, أم (am) is the specific word for "or" used in questions where you are asking the listener to choose between two options. The other word for "or", أو (aw), is mostly used in regular statements.

Why does السيارة (car) have ال (al-) if the English translation is just "this car"?

In Arabic, to say "this [noun]", the noun must include ال (the). So, هذه السيارة literally translates to "this the car". If you dropped the ال, the phrase هذه سيارة would mean "This is a car" instead.

Why do جديدة (new) and قديمة (old) end with the letter ة (taa marbuta)?