It's not worth ... about. (worry)
worrying
It's difficult ... (learn) a new language.
to learn
... (play) scrabble is my favourite hobby.
Playing
I don't like ... (do) housework.
doing
I'm looking forward to ... (relax) on holiday.
relaxing
I'm bored with ... (cook).
cooking
I'd like ... (have) a Porsche.
to have
Don't forget ... (lock) the door.
to lock
Please, stop ... (sing)!
singing
Is he afraid of ... (talk) to people?
talking
They told me how much ... (pay).
to pay
... (ski) is easy.
Skiing
She's going to Australia ... (see) kangaroos.
to see
He is too young ... (drive) a car
to drive
They are very good at ... (dance).
dancing
He decided ... (go) to New York.
to go
I don't know when ... (call) you.
to call