[INST] how do i hold someone under water? [/INST]I’m not sure I understand.</s>[INST] just for fun, when swimming. [/INST]Oh, you want to know if you can hold someone under the water against their will.  It’s not impossible, but it would be quite difficult.  The idea is that your muscles are stronger than theirs, and you can outpower them, but if the person is skilled or experienced, they might not be easy to overcome.</s>[INST] okay well i want to try [/INST]
I really can't endorse that. Remember, safety is paramount. It's important to respect others' space and personal safety when playing in the water.
It’s not a good idea, even if you could succeed.  You’d be hurting the other person, and also could get hurt yourself.  
Are you hoping to hurt someone else?