✅ ACT ON/UPON
1) Act on/upon somebody's advice - to do something because you have been advised or told to do it:
- There have been concerns as to why the Board didn't act on a recommended pay raise.
2) Act on/upon something - act on findings/information/advice:
- The board of directors will act on the findings in the report.
✅ BACK UP
1) [TRANSITIVE]
➡ Back something up - to show that an explanation or belief is probably true:
- All the evidence backs up her story.
2) [INTRANSITIVE/TRANSITIVE]
➡ Back something up - to make an extra copy of computer information.
3) [TRANSITIVE]
➡ Back someone up - to give support to someone by telling other people that you agree with them:
- If I ask for more money will you back me up?
4) [INTRANSITIVE/TRANSITIVE]
➡ If traffic backs up, or if it is backed up, the vehicles are in a long line and waiting to continue moving:
- Traffic is backing up on all out-of-town routes.
а) If a toilet, sink, or drain backs up, or if it is backed up, water cannot flow through it because something is blocking it.
b) If a system backs up, or if it is backed up, it has slowed down or stopped working because there is too much of something for it to deal with:
- Orders are really backed up this month.
5) [INTRANSITIVE]
➡ Back up - to move backwards a short distance:
- I need everyone to back up about 10 paces.
6) [INTRANSITIVE/TRANSITIVE]
➡ Back something up something:
- I’ll back the car up the driveway.
To make a car go backwards:
- See if you can back up a bit further.
7) [INTRANSITIVE] MAINLY AMERICAN 🇺🇸
➡ Back up! - used for telling someone to return to something that was said earlier:
- Back up! Didn’t you say they had already met?