1. Dan always shares fun ways to learn English so that he can help students enjoy their English-learning journey. (TO) => Dan always

2. I turn on the English subtitles to understand what the actors say clearly. (SINCE)

=> I turn on the English subtitles

3. One of my ways to learn English vocabulary is to keep a note of new words when I come across them. (DOWN) => One of my ways to learn English vocabulary is

4. Songs can help you learn English because they provide varied vocabulary. (OF) → Songs can help you learn English 

1 Dan always shares fun ways to learn English in order to help students enjoy their English-learning journey.

- S + V + O + so that/in order to + S + V: Để mà...

- HTD: S + V(s/es) + O.

2 I turn on the English subtitles since I want to understand what the actors say clearly.

- S + V + O + because/since/as + S + V: Bởi vì.

- Want to do sth: Muốn làm gì.

3 One of my ways to learn English vocabulary is to jot down new words when I come across them.

- (to) jot down (phr v): Ghi chú nhanh.

- One of one's ways to do sth + be + ...: Cách làm gì của ai đó là gì.

4 Songs can help you learn English because they provide a variety of vocabulary.

- A variety of + N đếm được/không đếm được.

- Adj + N.

- Can + V-inf: Có thể làm gì.