The sentences are grammatically correct, but I can provide some observations and suggestions to improve clarity or precision:

1. "I wish I had more time to get to know your beautiful country better."

Correct as is.



2. "My little daughter was really impressed by the wonderful flowers in DaLat."

Consider specifying "in DaLat" for variety, e.g., "by the beautiful flowers."



3. "The design and material used to make the Ao dai for men were different from those used for women."

Precise and correct.



4. "People like wearing jeans because it did not wear out easily."

The verb tense should be consistent: "do not wear out easily" (present tense for a general truth).



5. "Internet is really wonderful. It’s very fast and convenient way to get information."

Add "a" before "very fast and convenient" for proper grammar: "a very fast and convenient way."



6. "You love playing chess with your father in your free time, don’t you?"

Correct as is.




Let me know if you'd like more detailed explanations!