Because sometimes Grammar can't be avoided...
Tenses? Adjectives? Modals?
If it is Oxford English what you like, with any kins of exercises and games, it is here
Y si quieres un curso entero con diferentes niveles y ejercicios de comprensión oral, pincha aquí
But, surely, one of the best places to practise all these things and many more is the British Council website: just click here
This is another place where you can find not only exercises, but also explanation on the forms, uses, exceptions, etc.here
Do you want to improve? You can also have some advanced grammar exercise, here