"I am agree" or "I agree"?
I am agree with you.
I agree with you.
The rule
"Agree" is already a verb, so it doesn't need "am / is / are." Say "I agree," not "I am agree."
This is one of the most common mistakes for English learners. "Agree" is a verb all by itself — like "think" or "know" — so you don't put a form of "be" in front of it. You wouldn't say "I am think," and it's exactly the same with agree.
Use it directly: I agree, she agrees, they agreed.
More examples
She is agree with the plan.
She agrees with the plan.
We were agree to meet later.
We agreed to meet later.
Are you agree?
Do you agree?
How to remember it
Treat "agree" like "think": you say "I think" and "I agree" — never "I am think" or "I am agree."
Frequently asked
Why is "I am agree" wrong?
Because agree is already a verb. Adding "am" gives you two verbs at once (am + agree). Just say "I agree," the same way you'd say "I understand" or "I know."
How do I say it in the past?
Use "agreed": "I agreed with her," not "I was agree with her."