Grammar fix
valid reason
good excuse
A fair or acceptable explanation for something, especially for not doing something or for a mistake.
collocationB1common
Hear it in context
Notice where the phrase sounds natural.
- She had a valid reason for missing the meeting—her son was sick.daily life
- In my opinion, students should only be allowed to submit assignments late if they have a valid reason, such as illness or a family emergency.IELTS speaking
Fix the pattern
Pattern: valid reason (for something/for doing something)
WrongShe had a valid reason of leaving.
RightShe had a valid reason for leaving.
A reason FOR something, not 'of'.
Patternvalid reason (for something/for doing something)
Use it right
Choose the version that sounds natural in speech.
Natural; 'legitimate justification' is formal/legal.
Build natural chunks
Words that usually travel with it.
a valid reason forforperfectlywithout agive
Don't confuse it
Compare with 'weak excuse,' which means a reason that is not convincing.