Hôm qua, An đã ngủ rất muộn vì xem phim.

Yesterday, An slept very late because he watched a movie.

Breakdown of Hôm qua, An đã ngủ rất muộn vì xem phim.

• An: An
• rất: very
• vì: because
• hôm qua: yesterday
• đã: (past marker)
• ngủ: to sleep
• muộn: late
• xem: to watch
• phim: the movie

Questions & Answers about Hôm qua, An đã ngủ rất muộn vì xem phim.

What is the function of đã in this sentence?

đã is the Vietnamese marker for past tense or completed action. Placed before the verb ngủ, it indicates that the sleeping happened in the past. Vietnamese verbs themselves do not change form for tense, so particles like đã (past), đang (continuous), or sẽ (future) are used instead.

Why is Hôm qua placed at the beginning? Can I move it elsewhere?

Hôm qua means “yesterday” and sets the time context. Vietnamese is flexible with adverbials, so you could say
– An đã ngủ rất muộn hôm qua vì xem phim.
but placing Hôm qua at the front (time–topic position) makes the sentence more topical and natural when you want to emphasize “yesterday” first.

Do we need both Hôm qua and đã since they both indicate past?

Not strictly. Hôm qua already tells you the action is in the past, so you could omit đã:
– Hôm qua, An ngủ rất muộn vì xem phim.
Including both is common for added emphasis on the past aspect or simply out of habit, but it’s not ungrammatical without đã.

What does rất muộn mean, and could we use muộn lắm instead?

rất muộn literally means “very late.” Seeing rất before an adjective or adverb intensifies it. You could also say muộn lắm (“late very”), which is equally correct but a bit more colloquial. The nuance:
– rất muộn feels slightly more formal/standard
– muộn lắm is more conversational

Why is it vì xem phim instead of vì đã xem phim or repeating the subject (vì An xem phim)?

1. vì introduces a cause/reason clause and does not require its clause to carry tense particles.
2. In Vietnamese, once the subject is clear (An), you often drop it in the subordinate clause. So vì xem phim is concise and natural. You could say vì An xem phim, but that’s more explicit and sometimes redundant.

Can we replace vì with bởi vì, vì vậy, or nên?

– bởi vì also means “because” and is interchangeable with vì, though bởi vì can sound a bit more formal or emphatic.
– vì vậy means “therefore” (result), not “because.”
– nên means “so” or “thus” (draws a conclusion). You could rephrase as:
An đã xem phim đến khuya, nên hôm qua ngủ rất muộn.
but that inverts cause and effect and uses nên to link them.

What is the typical word order in Vietnamese for a sentence like this?

The usual structure is:

1. (Time)
2. Subject
3. Tense/aspect marker (e.g., đã)
4. Verb
5. Complement/adverbial (e.g., rất muộn)

6. Cause/reason clause (introduced by vì, bởi vì…)

   So: Hôm qua (time), An (subject), đã (aspect), ngủ (verb), rất muộn (adverbial), vì xem phim (reason).