私（丁寧）
I keep my promises.
私は約束を守ります
I keep the promise I made with my friend.
私は友達とした約束を守ります
It's a promise I made with my friend, so I keep it.
私は友達とした約束なので約束を守ります
It's a promise I made with my friend, so I keep it even in a difficult situation.
私は友達とした約束なので難しい状況でも約束を守ります
It's a promise I made with my friend, so I keep it to the end even in a difficult situation.
私は友達とした約束なので難しい状況でも最後まで約束を守ります