(someone) is exhausted

"Exhausted" means "very tired".

When you want to emphasize the word "exhausted", you can use adverbs like these:

I'm so exhausted.

or

I'm completely exhausted.

However, it doesn't sound right to say "I'm very exhausted". That's because "very" is already included in the meaning of the word: "exhausted" means "very tired". Adjectives like this are sometimes called "ungradable" or "extreme" adjectives. Here are some more examples:

• horrible
• enormous
• terrible
• amazing
• delicious
• excruciating

By (some time), (sentence)

Use this phrase to talk about a continuing situation. You use "By ___" to describe the situation's progress at a certain point in time. For example:

By Saturday, the forest fire had reached several hundred homes.

If it keeps going like this, by next week, we will have raised over one hundred thousand dollars.

By noon on the first day, we were already yelling at each other and ready to go home.

physically and mentally (adjective)

"Physically" means related to someone's body or to solid objects. "Mentally" means related to someon's mind. These words often go together:

You need to be totally physically and mentally prepared before you even attempt it.

Sometimes the word "spiritually" gets included instead. It means related to someone's spirit or soul.

After Merill died, I was in pain physically, mentally, and spiritually, for quite a long time.