Definition - A construction that consists of two clauses that have a shared word or phrase is called apo koinou. The word or phrase that the clauses share is called the koinon.

Example -
I like tennis is my favourite sport.
(In the above the word tennis is the koinon because it is shared by the two clauses I like {tennis} and {tennis} is my favourite sport.

Etymology -
The term means "common" in Greek.

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