3. Auxiliary and modal verbs (5)

3. Auxiliary and modal verbs (5)

In British English, but not American, do can be used alone as a substitute verb after an auxiliary verb. In such cases, the auxiliary verb is stressed. Click here to see the full text.  

AE	BE
—Will you go to the party?	—Will you go to the party?
—I may. I haven't decided yet.	—I may (or I may do). I haven't decided yet.
He didn't pass the test, but he could have if he had studied a little harder.	He didn't pass the test, but he could have (or he could have done) if he had studied a little harder.