Answer:
They watched TV last night.
Step-by-step explanation:
I couldn't find the complete form to this question online. But since it has an adverb of time: "last night", we can deduce that the verb tense to which the verb "watch" must be passed is a simple past tense.
These types of adverbs tell us just when the action of our sentence happens.
While the simple past tense serves to indicate something that happened at a specific time in the past, and there it ended. In this case, it happened last night.
Next I will write the verb conjugated in the past simple for each of the people in English:
- I watched
- you watched
- he/she/it watched
- we watched
- you watched
- they watched