They ___can_ speak Japanese.(+)
I __could__read when I was 5. (+)
-I`ve got a headache.-You __should_ go to the doctor.(+)
You __must not__ drop the litter in the streets.(-)
My shcool starts at 8 o`clock. I __have to__ get up at 7.(+)
You __shouldn't__ pay when the tickets are free.(-)
You __must not__ cheat in the classroom. You`ll get into trouble, you know.(-)
You __shouldn't__ drink so many milkshakes - you`ll turn green and enormously fat.(-)
A human __can__ write letters, but a dog _can't___.(+/-)