Student or Learner
Are these sentences natural to a native ear?
1. There is a lot of deposit on that heaterís coil ( I was talking about the coil of a water heater that was covered with a grey material)
2. I just want to echo what John was saying earlier.
3. Have you recently made enemies with someone who might have had access to your unit.
Please be aware that I'm neither a native English speaker nor a teacher.