Question

1. He has a severe illness.
2. He has a serious illness.

3. He is severe.
4. He is serious.

(Are both the same and interchangable?)

Answer 1

In sentences 1 and 2, they are interchangeable, but not in sentences 3 and 4.

In sentence 3, "severe" means he treats other people harshly.

In sentence 4, "serious" means he is not joking around!