About: Suppose, supposing and what if

What's the difference? When to use them?

Meaning: SUGGESTIONS
We use suppose, supposing and what if + present verb form to make suggestions about what might happen:

Examples:
1. Suppose we meet in the offices downstairs at four o’clock?

2. Supposing I don’t bring my car and you and I travel together. That would save us half the cost of petrol and parking.

3. What if we find the candles and put them around the room?

Meaning: POSSIBILITY
When we are less certain, we use suppose, supposing and what if + past form to talk about future possibility:

Examples:
1. Suppose we asked Mary to baby-sit? Do you think she’d do it? (not as certain as Suppose we ask Mary to baby-sit?)

2. Supposing someone else wrote the essay. How would we know? (not as certain as Supposing someone else writes the essay)

3. What if I gave up working full-time. I’d love that.

When we refer to something that did not happen (something hypothetical), we use the past perfect:

Examples:
1. Suppose we hadn’t brought our umbrellas. (We did bring our umbrellas.)

2. Supposing they had closed the road. Would that have been a good idea? (They didn’t close the road.)

3. What if I had accidentally told Maria about the party! That would have ruined the surprise. (I didn’t tell Maria about the party.)

Remember:
We use be supposed to to talk about obligations and arrangements, not suggestions.

Example:
You are supposed to put money in the parking meter!