Writing: About to

About to
<<Be + About + To + Infinitive>>
It is used to described something which is going to happen very soon.
If you are about to do something, you are going to do it very soon.
យើងប្រើវាដើម្បីនិយាយអំពីអ្វីមួយដែលវារៀបនឹងកើតឡើងឆាប់ៗនៅពេលអនាគតដ៏ខ្លីខាងមុខ។
Example:
- Don't go out now! We're about to have dinner.
- I was about to go to bed when my friend called me.

Source: OXFORD