Agree

1. Typical mistakes: 

I am agree with you. 

We not agree. 

'Agree' is a b verb, not an adjective. 

I agree with you. 

We don't agree. 

2. 'Agree' can be used with an infinitive or a 'that-clause'. 

He agreed to send me a cheque (Not: He agreed sending me...). 

She agreed that I was right. 

3. Several prepositions are possible, depending on the meaning and context. 

a. You agree about a subject of discussion: 

 They never agree about politics. 

b. You agree on a matter for decision: 

 Can we agree on a date for the next meeting? 

c. You agree to a proposal: 

He's agreed to our suggestion about the holiday. 

d. You agree with an opinion, an idea, an analysis, an explanation, etc: 

I completely agree with your views on Jolie. 

e. You agree with a person: 

It's a good idea to agree with the boss most of the time. 

4. A passive structure in possible with plural subject; this is rather formal: 

Are we all agree, gentlemen? 

The committee are agreed that it would be a mistake to speed any more money on the project.