Inflections of 'agree' (v): (⇒ conjugate)
v 3rd person singular
v pres pverb, present participle: -ing verb used descriptively or to form progressive verb--for example, "a singing bird," "It is singing."
v pastverb, past simple: Past tense--for example, "He saw the man." "She laughed."
v past pverb, past participle: Verb form used descriptively or to form verbs--for example, "the locked door," "The door has been locked."
WordReference Collins English Usage © 2019
If someone says something and you say ‘I agree’, you mean that you have the same opinion.
‘That film was excellent.’ – ‘I agree.’
‘agree with’
You can also say that you agree with someone or agree with what they say.
I agree with Mark.
He agreed with my idea.
Be careful
Don't say that you ‘agree something’ or ‘are agreed with’ it. Also, when you use ‘agree’ in this sense, don't use the progressive. Don't say, for example, ‘I am agreeing with Mark’.
‘agree to’
If you agree to a suggestion or proposal, you say that you will allow it to happen.
He had agreed to the use of force.
However, don't say that someone ‘agrees to’ an invitation. You say that they accept it.
He accepted our invitation to the dinner party.
If someone asks you to do something and you agree to do it, you say that you will do it.
She agreed to lend me her car.
She finally agreed to come to the club on Wednesday.
Be careful
Don't say that you ‘agree doing’ something.
‘agree on’
If people reach a decision together about something, they agree on it.
We agreed on a date for the wedding.
‘agree that’
You can say what the decision is using agree and a that-clause.
They agreed that the meeting should be postponed.
The passive form ‘It was agreed that...’ is often used.
It was agreed that something had to be done.
'agree' also found in these entries:

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