my daughter starting sitting up around 4 months and started walking at 7 months. baby will get there when its time .

Every baby reaches milestones at different times, I'm sure he is fine, just hasn't gotten the hang of it. Remember, don't compare your babe to anyone else's or it will drive you crazy! My daughter was lazy, she sat up unassisted around 8-9 months I think and didn't start walking until 14 months!

6-8 months

My son just started sitting up a couple days ago, he's 5 months.

I babysit a 7 mo old and she can sit up but she isn't strong enough to keep herself up for more than a few seconds

my niece sit up at 5 months

my daughter was sitting up on her by 6 months at 7 months she was a pro. Your baby will do it eventually its completely normal for them to not be able to sit up by themselves for very long

only babies know their limit.

yeah their back is still fragile by 9-10 months they should sit up longer.