His weakness is his inability to say no.

I weaken, you weaken, he/she/it weakens, we weaken, you weaken, they weaken.

She weakens her weakness.

Dyslexia is a challenge for many students.

The sales figures are weakening slightly this quarter.

This bad news will weaken his position.

He is weaker than his brother.

He is struggling and needs rest.

You are struggling in your efforts, but don't give up!

If you were to falter, you would be better off resting.