Hi I'm a beginner in English. I'm confused about the grammar in English.
This sentence is an explanation for the verb implement means from Oxford learners dictionary
to make something that has been officially decided start to happen or be used
Q1: In the sentence there is decided in it. I wonder about decided whether it is a passive form from of the infinitive verb decide or a new word typed adjective.
Q2: Is start to happen or be used same as start to happen or start to be used?
Q3: I know that is a relative clauses and it seems to be used for something, but why doesn't leave out even is an object?