Onun senden daha genç olduğunu unutmamalısın.
- You must keep in mind that she's much younger than you.
Sana söylediğimi unutma.
- Keep in mind what I tell you.
Bear in mind that I'm not as young as I was, so don't walk so fast.
Keep in mind that he does not hear too well anymore, so you may have to speak more loudly.