I don’t think this is something you can force. Every child will reach stages in their own time.

Agree with the answers already – babies achieve their milestones in their own time. They’ll mostly do it themselves over time & with practice pushing up, rolling over etc. You can try propping up with cushions or pillows while playing – I used to use a u shape pillow on top of other pillows to give height. But only when my babies were strong enough and interested in sitting – used the pillows for support and for when they fell sideways or back.
I’m not a huge fan of bumbo type seats in babies who can’t yet sit independently- can affect their posture & muscle development. (From the position they’re in when in the bumbo. But a great aid when they can support themselves.

Tummy time really helps as strengthens neck, back and abdo muscles.
Or if you’re worried about bubs development or muscle tone then check with GP or a nurse.

But I’d say stick with lots of floor play, tummy time and different activities that catch bubs eye and encourage different movements. They get there in their own time.

My second child is the only one who was sitting on her own at 7 months
My first could sit at 8 months, but my third has only been able to sit on his own since about 11.5 months! My third has been quite slow – we were seeing a physio to help him along with his gross motor skills, as he was a bit behind.

At 7 months, a lot of babies aren’t ready/able to sit up on their own. Lots of tummy time can help, but if you are really concerned, try seeing your child health nurse as they see lots and lots of babies and can tell you where you’re little one is at and if they feel your baby is a bit behind can refer you to a physio who can give a bit of help.
Good luck! They will get there eventually!

I can only suggest propping him in the sitting position with lots of pillows and cushions. I don’t really know if it will help, but it’s worth a try. Babies generally do things at their own pace, when they’re ready. But if his lack of sitting continues and worries you, I suggest a trip to the GP or health nurse for a check up

he will when he is ready to and when his muscles are strong enough.

My daughter at 7 months wasn’t sitting up on her own she is now 8 1/2 months old and sits up sometimes falls over but we always place a pillow behind her the bendy ones are great one in front of her and she loves it! Good practice !

Do you mean he is not sitting up? I found that anytime I was worried about a milestone my baby met it a week later. You can use a bumbo but if he is not sitting up he needs to develop the muscles – ie tummy time

We used a bumbo seat to start off with to get them used to sitting up and then trialled them by themselves and it worked for us. Good luck!