Learn Arabic (Modern Standard): هل عندك وقت يوم الأحد؟

In Arabic, there is no direct verb for "to have". Instead, you use the preposition عند (meaning "with" or "at") attached to a pronoun suffix. So عندك literally means "at you" or "with you". The ending can be pronounced 'indaka if asking a male, or 'indaki if asking a female.

Why do we say يوم الأحد instead of just الأحد for "Sunday"?

While you can sometimes just say الأحد to mean "Sunday", it is very common and natural in Arabic to use the word يوم (day) followed by the specific day's name. This forms an "Idafa" (possession phrase) literally meaning "the day of Sunday".

Why doesn't the word يوم have "al-" (the) before it, since we are talking about a specific day?

In an Idafa (possession structure) like يوم الأحد, the first word never takes the definite article prefix الـ (al-). The whole phrase automatically becomes definite because the second word, الأحد, has الـ.

Why doesn't وقت (time) have "al-" (the) attached to it?

The word وقت is indefinite here because we are asking if they have "any time" or "some time" in general. If we added "al-", it would mean "Do you have the time?" (as in asking what time it is on the clock).