not easy in English:

I feel tense and agitated when I have too much work to do.

Every muscle in his body was tense and ready to attack.

tense situation/atmosphere/moment

The international situation had become so tense, it would require proficient diplomats to handle it with kid gloves.

I say "should", because theses written in the present tense are still seen around and about.

The future progressive tense is used when expressing events and action in progress at some future point, however the example sentence cannot be understood in that way.

It's very interesting that in Chinese the concept of tense does not exist.

Adverbial time clauses (here 'when') write about the future in the present tense.

These sentences only differ with respect to tense.

The example is a past progressive tense sentence. How was everybody taught when they were learning about progressive tense?

In the official question collection it is explained as being "passive voice of the present continuous tense".

I’m feeling a bit tense and nervous about my job interview tomorrow.

I felt very tense about driving, and the test was a disaster.

An example of tense is the way to describe a student just before he takes a big and important test.

I have been feeling rather tense all day

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.

It was a challenging project, but also an exciting one.

Teaching young children is a challenging and rewarding job.

I like the new guy. He's not afraid to take on challenging work.

your task is challenging but you can do it

I have a very challenging job but I enjoy it.

Solving Rubik`s cube is challenging

Her work is very challenging. It tests her abilities and keeps her interested.

This project seems challenging so we will have to do our best

My job is challenging and rewarding.

I like challenging sports

This job is challenging.

Being a teacher is a challenging job because it isn’t easy to deal with children.

Aren't you too fragile for such a challenging job?

A challenging job is very difficult, but in an enjoyable way.

My job is very challenging, every day I have to learn new things