Since and for are both used to express a duration of time, but they are used in different ways. Here is the breakdown of how each word is used in the provided sentences:
1. ... we had lunch - for
Explanation: The phrase "we had lunch" refers to a specific moment in the past, so we use "for" to indicate the duration of time before that moment. Example: We had lunch for one hour.
Answer: We had lunch for one hour.
2. ... one hour - for
Explanation: The phrase "one hour" refers to a specific duration of time, so we use "for" to indicate that duration. Example: I studied for one hour.
Answer: I studied for one hour.
3. I left school - Since
Explanation: The moment "I left school" refers to a specific point in the past, so we use "since" to indicate the starting point of a time period that continues until now or another specified time. Example: I haven't seen my friend since I left school.
Answer: I haven't seen my friend since I left school.
4. ... two months - for
Explanation: The phrase "two months" refers to a specific duration of time, so we use "for" to indicate that duration. Example: I traveled for two months.
Answer: I traveled for two months.
5. Sunday morning - Since
Explanation: The noun phrase "Sunday morning" refers to a specific point in the past, so we use "since" to indicate the starting point of a time period that continues until now or another specified time. Example: I've been waiting for your call since Sunday morning.
Answer: I've been waiting for your call since Sunday morning.
6. ... three weeks - for
Explanation: The phrase "three weeks" refers to a specific duration of time, so we use "for" to indicate that duration. Example: I stayed at the beach for three weeks.
Answer: I stayed at the beach for three weeks.
7. ... this afternoon - Since
Explanation: The noun phrase "this afternoon" refers to a specific point in the past, so we use "since" to indicate the starting point of a time period that continues until now or another specified time. Example: I've been playing tennis since this afternoon.
Answer: I've been playing tennis since this afternoon.
8. ... five minutes - for
Explanation: The phrase "five minutes" refers to a specific duration of time, so we use "for" to indicate that duration. Example: I waited for five minutes for the bus.
Answer: I waited for five minutes for the bus.
9. ... she was a baby - Since
Explanation: The phrase "she was a baby" refers to a specific point in the past, so we use "since" to indicate the starting point of a time period that continues until now or another specified time. Example: I've known her since she was a baby.
Answer: I've known her since she was a baby.
I hope this explanation helps clarify the use of "since" and "for" in different contexts of time. Let me know if you have any further questions!
1. ... we had lunch - for
Explanation: The phrase "we had lunch" refers to a specific moment in the past, so we use "for" to indicate the duration of time before that moment. Example: We had lunch for one hour.
Answer: We had lunch for one hour.
2. ... one hour - for
Explanation: The phrase "one hour" refers to a specific duration of time, so we use "for" to indicate that duration. Example: I studied for one hour.
Answer: I studied for one hour.
3. I left school - Since
Explanation: The moment "I left school" refers to a specific point in the past, so we use "since" to indicate the starting point of a time period that continues until now or another specified time. Example: I haven't seen my friend since I left school.
Answer: I haven't seen my friend since I left school.
4. ... two months - for
Explanation: The phrase "two months" refers to a specific duration of time, so we use "for" to indicate that duration. Example: I traveled for two months.
Answer: I traveled for two months.
5. Sunday morning - Since
Explanation: The noun phrase "Sunday morning" refers to a specific point in the past, so we use "since" to indicate the starting point of a time period that continues until now or another specified time. Example: I've been waiting for your call since Sunday morning.
Answer: I've been waiting for your call since Sunday morning.
6. ... three weeks - for
Explanation: The phrase "three weeks" refers to a specific duration of time, so we use "for" to indicate that duration. Example: I stayed at the beach for three weeks.
Answer: I stayed at the beach for three weeks.
7. ... this afternoon - Since
Explanation: The noun phrase "this afternoon" refers to a specific point in the past, so we use "since" to indicate the starting point of a time period that continues until now or another specified time. Example: I've been playing tennis since this afternoon.
Answer: I've been playing tennis since this afternoon.
8. ... five minutes - for
Explanation: The phrase "five minutes" refers to a specific duration of time, so we use "for" to indicate that duration. Example: I waited for five minutes for the bus.
Answer: I waited for five minutes for the bus.
9. ... she was a baby - Since
Explanation: The phrase "she was a baby" refers to a specific point in the past, so we use "since" to indicate the starting point of a time period that continues until now or another specified time. Example: I've known her since she was a baby.
Answer: I've known her since she was a baby.
I hope this explanation helps clarify the use of "since" and "for" in different contexts of time. Let me know if you have any further questions!