exhausted - exhausting - exhaustive
If you are exhausted, you are very tired.
At the end of the day I felt exhausted.
All three men were hot, dirty and exhausted.
Don't use words such as ‘rather’ or ‘very’ in front of exhausted. You can, however, use words such as completely, absolutely, or utterly.
‘And how are you feeling?’ – ‘Exhausted. Completely exhausted.’
The guest speaker looked absolutely exhausted.
If an activity is exhausting, it is very tiring.
It's a difficult and exhausting job.
Carrying bags is exhausting.
An exhaustive study or description is thorough and complete.
He studied the problem in exhaustive detail.
For a more exhaustive treatment you should read Margaret Boden's book.