Fragments are incomplete sentences used as complete sentences. Fragments are common in normal speech but shouldn’t be used in formal writing.
Speaking
- ‘When’s his birthday?’
‘October.’
(fragment) - ‘What did he do?’
‘Shut the door and left.’
(no subject but in a conversation it is OK)
Writing
Looking forward to seeing you.
(no subject)
I’m looking forward to seeing you.
(in writing you need to add a subject/I’m)
