Agree to/ with

[Humble]

Hi,
I wonder if all my sentences are correct and equally common.
1. They agreed to the proposal.
2. They agreed with the proposal.
3. They agreed to the suggestion/ plan.
4. They agreed with the suggestion/ plan.
Is there any difference in the register etc?

TIA

[MikeNewYork]

Hi,
I wonder if all my sentences are correct and equally common.
1. They agreed to the proposal.
2. They agreed with the proposal.
3. They agreed to the suggestion/ plan.
4. They agreed with the suggestion/ plan.
Is there any difference in the register etc?

TIA

No difference in register. All are correct and common.

The difference is in meaning. With the "to" forms, they are part of the proposal, suggestion, plan. They will be expected to do something.

With the "with" forms, they may or may not be participating. The agreement may be only philosophical.

[Humble]

Thanks, Mike!

[MikeNewYork]

Thanks, Mike!

You're welcome, Humble.