1. Because he is too old, he can hardly do anything
=> His age prevents him from doing anything.
2. Although Lan didn't feel well, she went to work.
=> In spite of not feeling well, Lan went to work.
3. My sister is a hard student. She always does her homework before going to class.
=> My sister, who is a hard student, always does her homework before going to class.
4. With hard work, he can improve his pronunciation quickly.
=> If he works hard, he will improve his pronunciation quickly.
HỌC TỐT!