1. Adverbs of time

2. When: at that time
When I was 21, I started to work in the beauty salon on Alvarado.
I began to work at the beauty salon on Alvarado when I was 21.

3. After
After I had worked in the salon for three years, I was able to buy it from the owner.
I was able to buy the salon from the owner after I had worked there for three years.

4. Until: up to that time
I didn’t have any interest in owning a salon of my own until Mary offered to sell hers.
Until Mary offered to sell her salon to me, I didn’t have any interest in owning my own business.

5. Since: from that time in the past until the present
I have had a job since I was 15 years old.
I have owned my salon since 1999.
I have enjoyed myself since I began working on Alvarado street.
I have been thinking about hiring another employee since I bought my salon.

6. While: continuous action
A. two things happening at the same time
While I was cutting Susan’s hair, she was telling me all about her life.
B. An on-going action interrupted by another action
While we were talking, her husband came in to say hi.

7. During: describes an event
I couldn’t concentrate on my studies during high school.
During high school, I never paid attention to my teacher.
I lived in Spain for two years. I was really happy during that time.

8. Talking about time For: amount of time
I have had this salon for six years.
I have been studying for two hours/a week
Since: usually a date or specific time.
I have had this salon since 1999.
I have been studying grammar since this morning/last night/3pm