-ing as a subject

When an activity is the subject of a sentence, use the -ing form of the verb. It works like a noun: it can come first, and the verb after it is singular.

With an object or more words

The -ing word can have its own object or other words after it. The whole group is the subject, and the verb is still singular.

Not

Put not before the -ing word.

It is … to

You can also start with it and put to + verb at the end. This is common in speech.

Common mistakes

Don't start the sentence with the base verb. And the verb after the -ing group is singular, even when its object is plural: the subject is one activity.

• × Swim is good for you. → Swimming is good for you.
• × Watch films helps my English. → Watching films helps my English.
• × Reading books are fun. → Reading books is fun.