sắp

1. Basic Usage
Place sắp directly before a verb or an adjective to indicate that an action is about to happen or a state is about to change (e.g., Trời sắp tối - It is about to get dark). Unlike sẽ, which is used for the general, open-ended future, sắp means the event is happening soon relative to its scale. This could mean moments away for a daily task, or weeks away for a major life event like studying abroad. To emphasize that something is on the absolute verge of happening, you can use the variant sắp sửa.

2. The 'Sắp ... rồi' Pattern
You will frequently hear sắp paired with rồi at the end of the sentence (e.g., sắp xong rồi - almost done). Even though learners often associate rồi with completed past actions, in this specific pattern it does not mean 'already'. Instead, it adds emotional weight, anticipation, or reassurance that the event is happening soon.

3. Asking 'Almost Done?'
To ask if something is about to happen or if someone is almost finished, you can use the pattern sắp ... chưa? (e.g., Sắp xong chưa? - Are you almost done?). This combines sắp with the question word chưa to check on the progress of an imminent event.

4. Not a Strict Tense
Because Vietnamese uses aspect markers rather than strict Western tenses, sắp is not bound only to the present-future. It can also describe an imminent action in the past that was interrupted. For example, Tôi sắp đi thì khách tới (I was about to leave when the guests arrived). Notice that we use the conjunction thì to link the clauses for this specific setup, rather than a word for 'when' like khi.

5. Negating 'Sắp'
To say that something is not about to happen, or to answer a sắp ... chưa? question negatively, do not use không sắp. Instead, drop sắp entirely and use chưa (not yet). For example, the natural negative response to Sắp xong chưa? is simply Chưa or Chưa xong.