Question

Why it is called building when it is already built?????

Answer 1

building refers to 2 things.
one is a noun and other is a verb
the one which is noun means a storied structure where people live and the other means a continuous verb which means a thing is being constructed

Answer 2

⏩➡⏩building is the name given to the structure

⏩➡⏩building refers to the structures like flats or malls which are tall or big

⏩➡⏩ building has two meanings... one in the form of verb and one in the form of noun

⏩➡⏩ in the form of verb it means that "to make"

⏩➡⏩ in the form of noun it means "a tall monument or structure"

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hope it helps ☺