17 put the verbs in brackets into the correct past tense.
1 a: did you see (you/see) fred at the airport?
b: no, he
(already/ check in) by the time i
(get) there.
2 a: the kidnappers finally (return) the child to
his parents yesterday.
b: thank goodness! they
(hold) the poor boy for
two weeks before they
(release) him.
3 a:
(you/do) anything interesting last night?
b: no, i just
.(watch) a dvd
(rent) the night before and then .. (go) to bed early.
4a: the police
(find) elizabeth's car last night.
b: oh? i
(not/know) she
(report) it stolen.
5 a:
(helen/help) you with the chores?
b: sure. while i (clean) the windows she
(vacuum) the carpets.

1a: Did you see (you/see) Fred at the airport?
b: No, he (already/checked in) by the time I (got) there.

To form the past simple tense, we need to change the verbs in brackets to their past tense forms:
1a: Did you see Fred at the airport?
b: No, he had already checked in by the time I got there.

Explanation:
In this conversation, person b is stating that Fred had already checked in at the airport before person a arrived. We use the past perfect tense ("had checked") to express an action that happened before another action in the past ("I got there").

2a: The kidnappers finally (returned) the child to his parents yesterday.
b: Thank goodness! They (had held) the poor boy for two weeks before they (released) him.

To form the past simple tense, we need to change the verbs in brackets to their past tense forms:
2a: The kidnappers finally returned the child to his parents yesterday.
b: Thank goodness! They had held the poor boy for two weeks before they released him.

Explanation:
In this conversation, person a is expressing that the kidnappers returned the child to his parents yesterday. Person b then responds with relief, stating that they had held the poor boy for two weeks before finally releasing him. We use the past perfect tense ("had held" and "had released") to express actions that happened before a specific time in the past ("yesterday").

3a: (Did you do) anything interesting last night?
b: No, I just (watched) a DVD (that I had rented) the night before and then (went) to bed early.

To form the past simple tense, we need to change the verbs in brackets to their past tense forms:
3a: Did you do anything interesting last night?
b: No, I just watched a DVD that I had rented the night before and then went to bed early.

Explanation:
In this conversation, person a is asking if person b did anything interesting last night. Person b responds by saying that they only watched a DVD that they had rented the night before and then went to bed early. We use the past simple tense ("watched" and "went") for actions that happened at a specific time in the past.

4a: The police (found) Elizabeth's car last night.
b: Oh? I (didn't know) she (had reported) it stolen.

To form the past simple tense, we need to change the verbs in brackets to their past tense forms:
4a: The police found Elizabeth's car last night.
b: Oh? I didn't know she had reported it stolen.

Explanation:
In this conversation, person a states that the police found Elizabeth's car last night. Person b responds with surprise, saying that they didn't know she had reported it stolen. We use the past perfect tense ("had reported") to express an action that happened before another action in the past ("I didn't know").

5a: (Did Helen help) you with the chores?
b: Sure. While I (cleaned) the windows, she (vacuumed) the carpets.

To form the past simple tense, we need to change the verbs in brackets to their past tense forms:
5a: Did Helen help you with the chores?
b: Sure. While I cleaned the windows, she vacuumed the carpets.

Explanation:
In this conversation, person a is asking if Helen helped person b with the chores. Person b responds by saying that Helen did help, and while person b cleaned the windows, Helen vacuumed the carpets. We use the past simple tense ("cleaned" and "vacuumed") for actions that happened at a specific time in the past.