All phrases

Nevertheless...

I understand your argument.

Your argument is reasonable and well-founded.

I share your opinion.

I completely agree with you.

I completely agree.

My opinion is identical to yours.

I acknowledge the correctness of your statement.

I respectfully disagree.

I have doubts.

I have a different opinion.

I have some doubts or concerns.

I'm not persuaded by your argument.

Your statement is partially incorrect.

I'm hesitant to agree completely.

I hold a different opinion.

In contrast to what you said...

That point is open to discussion or disagreement.

I would claim or assert that...

I would maintain or assert that...

Nevertheless, despite that...

On the other hand...

In spite of that...

Despite that...