I don't know when ... (call) you.
to call
... (play) scrabble is my favourite hobby.
Playing
Is he afraid of ... (talk) to people?
talking
He decided ... (go) to New York.
to go
She's going to Australia ... (see) kangaroos.
to see
I'd like ... (have) a Porsche.
to have
They are very good at ... (dance).
dancing
It's difficult ... (learn) a new language.
to learn
Please, stop ... (sing)!
singing
I'm bored with ... (cook).
cooking
It's always nice ... (get) chocolates.
to get
... (ski) is easy.
Skiing
He spent four hours ... (study) vocabulary.
studying
They told me how much ... (pay).
to pay
I don't like ... (do) housework.
doing
Don't forget ... (lock) the door.
to lock
Let's try ... (run) faster.
to run