No estoy de acuerdo con esa idea.

I

Breakdown of No estoy de acuerdo con esa idea.

• con: with
• la idea: the idea
• esa: that

Questions & Answers about No estoy de acuerdo con esa idea.

Why is it estoy and not soy?

Because Spanish uses the fixed expression estar de acuerdo for to agree / to be in agreement.

So you say:

• Estoy de acuerdo = I agree
• No estoy de acuerdo = I don’t agree

Even though agreement can feel like a more permanent opinion in English, Spanish still uses estar, not ser, in this expression. Saying soy de acuerdo is not correct.

What does de acuerdo mean here?

De acuerdo is a set phrase meaning in agreement.

So:

• estar de acuerdo = to agree
• no estar de acuerdo = to disagree

It’s best to learn it as a chunk, not word by word.

Also, de acuerdo can mean okay / all right in other contexts:

• —Vamos a las seis. —De acuerdo.
  —Let’s go at six. —Okay.

But in your sentence, it clearly means in agreement.

Why is con used after de acuerdo?