Если упражнение связано с глаголом "can":
1. Can you swim? No, I can't.
2. Can you see the hen? No, I can't.
3. Can hens fly? No, they can't.
4. Can his hen run? No, it can't.
5. Can his dog sing? No, it can't.
Если упражнение связано с глаголом "do/does" :
1. Do you swim? No, I don't.
2. Do you see the hen? No, I don't.
3. Do hens fly? No, they don't.
4. Does his hen run? No, it doesn't.
5. Does his dog sing? No, it doesn't.