sms on I-Q

I live in water
if you cut my tail i am a fruit
if you cut my head I am at your door
if you cut both then i am with you all the time?
What is this thing ....
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Answer:
Pearl- lives in water
Pear (cut off tail or "L") - a fruit
Earl (cut off head, or "P") - at your door
Ear (cut of both P & L)- you have an ear that is with you