Present simple
Habits, facts, and how things usually are. To say no or ask, add do or does: I don't fold up, he doesn't fold up.
- I / you / we / they fold up
- he / she / it folds up
plier
Regular verb, phrasal verb.
Phrasal verb: up
Only fold changes; up stays the same: folded up, folded up.
In speech, the helping verbs shorten: I’m, he’s, we’re, I’ve, I’ll, I’d.
Enough to talk about now, the past, and your plans, and to give instructions.
Habits, facts, and how things usually are. To say no or ask, add do or does: I don't fold up, he doesn't fold up.
What is happening now, and plans already arranged: we’re leaving tomorrow.
A finished action at a past time: yesterday, in 2020. To say no or ask, add did: I didn't fold up.
Plans and intentions, and what you can see coming: it’s going to rain.
Orders, advice, and instructions. Let’s suggests doing it together. To say no: don't fold up.