1. the suitcase was so heavy that he couldn't carry it
2. susan is so young that he can't go to the cinema alone
3. she was so tired that she couldn't eat
4. my grandfather is so old that he can't walk without a stick
5. the boy is so young that he can't understand the story
6. that dress was so expensive that i couldn't buy it
7. the weather was so warm that i didn't need a coat
8. she had so many exercises that she had to stay update to do them
9. the girl is so kind that we can make friends with/
10. the film is so interesting that i see it twice.