Is 11 am morning?
Yes, 11 a.m. is morning (one hour before noon/midday). Using the 24-hour clock (military time), it is written as 11:00.
You can say “Good morning” to someone at 11 a.m.
What time is morning can depend on context (e.g., 2 a.m. may be considered morning for someone starting an early work shift but nighttime for someone who went to bed at 11 p.m. and has been woken up by a noise).
Have you tried QuillBot’s free Paraphraser? It can help you find alternatives to time expressions such as “a.m.” and “noon.”