Are they skateboarding? (-)
No, they aren't
Are the boys playing basketball? (+)
Yes, they are
Are they playing chess? (-)
No, they aren't
Are the children skateboarding? (+)
Yes, they are
Are they cycling? (+)
Yes, they are
Are they doing judo? (+)
Yes, they are
Are they skipping? (-)
No, they aren't
Are they skipping? (+)
Yes, they are
Are they playing table tennis? (-)
No, they aren't
Are they surfing? (-)
No, they aren't
Are they playing chess? (+)
Yes, they are