1. We studied the Progressive Form of "V-te+iru".
The formal form of V-te+iru is: V-te+imasu.
(note: imasu is the formal form of iru)
For instance, the formal form of the sentence
"Tanaka-san, biiru nonde(i)ru" is:
Tanaka-san-wa, biiru-o nonde imasu.
(Try to use
particles in the formal style!)