1. I feel painful in my body.

Question

2. No pains, no gains.
3. No pain, no gain.
3. His stomach was so painful, so he
could not work at his workplace.
4. My eyes ache a lot.
5. My eyes feel painful, so I need to
take a rest.
6. I felt some pain in my intestines.
7. I felt like a beggar.

(Are the expressions all grammatical? Would you chek them and correct errors? Thank you.)

Answer 1

#1... You would say, My body feels painful.
#2 is not correct.
#3 you do not need "at his workplace".

The rest look good.