Final answer:
The sentence should be completed with the preposition 'for' to correctly state 'He lived abroad for many years.' The preposition 'for' is used to indicate the duration of time.
Step-by-step explanation:
The correct preposition to complete the sentence "He lived abroad ___ many years." is "for." Thus, the completed sentence should read: "He lived abroad for many years." The preposition 'for' is used to indicate the duration of time in which something happens.
Prepositions are words that show the relationship between a noun or a pronoun and other words in a sentence. They can indicate time, place, direction, and more. In this context, 'for' is being used to express the length of time that the individual lived abroad.
Example sentences using 'for' to indicate time duration include:
- I have worked here for five years.
- She read the book for two hours.