[Grammar] The lecture was so boring that I dropped off half way through.

[Rollercoaster1]

Is the word "through" fucntioning as an adverb, or as a preposition in the context below?
The lecture was so boring that I dropped of half way through.

 

[bhaisahab]

Yes, it's functioning as a preposition or adverb.

 

[Rollercoaster1]

Yes, it's functioning as a preposition or adverb.

What if I am taking an exam and this question appears on the examination paper?

 

[MikeNewYork]

I would not say preposition on an exam.