Since the gerund and the present participle have the same forms, sometimes it is difficult to decide whether an -ing form in a sentence is a gerund or a participle.

I’m busy refurnishing my room, don’t call me this weekend.
It’s no use crying over spilt milk.
It’s no good calling him, he’s abroad.
I had trouble starting my car this morning.
I had a hard time understanding what he was saying.

This structureThe way in which the parts of a sentence, clause or expression are arranged. E.g.: make somebody + infinitive in "The teacher made me rewrite the composition." is similar to have + somebody + infinitive. The difference is that the verbA part of speech that expresses an action or a state. E.g.: John seldom plays tennis. in present participle form refers to a repeated or continuousThe aspect expressing duration, formed with be + verb-ing. E.g.: What are you doing? actionA general term expressing that somebody or something does something.

His problems had him going to hospital for years.
We'll have my brother staying with us for a little while until he finds a new apartment.

be + verb-ing

Who is that smiling girl? (present participle)

The actionA general term expressing that somebody or something does something expressed with the present participle happens at the same timeA concept which is related to our perception of reality; that part of existence which is measured in seconds, minutes, hours, days, weeks, etc. as or just before another one.

The verbA part of speech that expresses an action or a state. E.g.: John seldom plays tennis.s come and go are often used with the present participle.

How often do you go swimming?
Let’s go dancing.

After these verbA part of speech that expresses an action or a state. E.g.: John seldom plays tennis.s the present participle expresses an actionA general term expressing that somebody or something does something in progressAn action is in progress when it is happening. E.g.: When I arrived he was surfing. ("he was surfing").

I saw him climbing over the fence. (= I saw him as he was climbing…)
I heard him singing in the bathroom. (= I heard him as he was singing…)

In passive voiceThe form of the transitive verb that shows whether the subject acts (active voice) or is acted upon (passive voice). a continuousThe aspect expressing duration, formed with be + verb-ing. E.g.: What are you doing? infinitive is used:

I saw him climb over the fence. (= I saw that he climbed…)
I have never heard this group perform this song. (= I have never heard this song performed by this group.)

After these verbA part of speech that expresses an action or a state. E.g.: John seldom plays tennis.s the infinitive expresses a completeA concept, related to the perfect aspect, expressing that an action has finished. E.g.: He’s finished university.d actionA general term expressing that somebody or something does something. If we mean an action in progressAn action is in progress when it is happening. E.g.: When I arrived he was surfing. ("he was surfing"), a present participle is used: