1. Sheila went by bus to save money.
2.peter has a part-time jpb to get some extra money.
3.My mother went to the post office to post some letters
4.Mary stayed at school until 9pm to finish her History project.

1.Sheila went by bus. She wanted to save money.
-> Sheila went by bus to save money.
2. Peter has a part-time job. He needs to get some extra money.
-> Peter has a part-time jpb to get some extra money.
3. My mother went to the post office. She had to post some letters.
-> My mother went to the post office to post some letters
4. Mary stayed at school until 9pm. She had to finish her History project.
-> Mary stayed at school until 9pm to finish her History project.