Recently, I've been troubled by severe tinnitus.

Nowadays, he goes to the gym every day.

Don't you think his behavior has been strange lately?

He seemed to be in trouble.

He is having trouble solving math problems.

Aldehyde is a very important compound in organic chemistry.

I think his behavior is unjust.

I think his actions are completely inhumane.

He was poisoned after eating something.

It seems like he has been poisoned by something.