II/ S + began/started + Ving/ to V1 + in/on/at + time
<-> S + have/has + V3 .. since +
1. We began studying Chinese in 2019.
=> We have studied Chinese since 2019.
2. She began to water the trees at six o`clock.
=>She ___________________________
3. They started working here last year.
=> They _______________________
4. He has collected stamps since 2020.
=>He began ________________________
1. We began studying Chinese in 2019.
=> We have studied Chinese since 2019.
2. She began to water the trees at six o`clock.
=>She has ___watered the trees since six o'clock.___
3. They started working here last year.
=> They ____have worked here since last year.___________________
4. He has collected stamps since 2020.
=>He began ____collecting stamps in 2020____________________
2. She has watered the trees since six o'clock
3. They have worked here since last year
4. He began collecting in 2020