khó in English:

It's too difficult.

It may seem like a minor thing to you, but for a lot of people this is really difficult to do.

Last night was very hot and muggy and it was difficult to sleep.

After a certain point, everything became a little more difficult.

It is difficult to love somebody when it's not clear whether or not the other person loves you the same way.

A good password should be difficult to guess, but easy to remember.

I agree with the ban in principle, but in practice it will be extremely difficult.

Anyway, I'm glad you were able to broach this difficult subject.

It's not as difficult to find a native speaker to help you with your language studies as it used to be.

Getting food to Fort Sumter would be a very difficult job.

A person who makes an easy matter sound difficult does not seem to be so smart.

Cutting a cake into equal pieces is rather difficult.

We're studying chemistry. Our lessons aren't difficult.

He just naturally avoids everything that is intense, difficult or strenuous.

In legal documents, difficult words and phrases are often used.