INTRODUCTION
The '-ing' form of the verb may be a present participle or a gerund.
The form is identical, the difference is in the function, or the job the word does in the sentence.
The present participle:
A participle is an adjective or part of a participial phrase qualifying a noun or a pronoun.
- Smiling, the lady told them they'd won the big prize.
- I heard them arguing last night.
The present participle is also used in the progressive aspect of verb tenses.
- I'm taking my brother to the station tonight
- The man was phoning his friend, when the lights went out.
This is most commonly used:
1. as part of the continuous form of a verb:
- He is painting
- She has been waiting
2. after verbs of movement/position in the pattern: verb + present participle,
- She sat looking at the sea
3. after verbs of perception in the pattern: verb + object + present participle
4. as an adjective:
- amazing,
- worrying,
- exciting,
- boring
The gerund:
The gerund is a verb which is used as if it were a noun. Since it is a verb, it can not be qualified by an adjective, nor preceded by an article, but, like other forms of the verb, it can be modified by an adverb and take a complement .
So it can be used:
1. as the subject of the sentence:
2. after prepositions:
- Can you sneeze without opening your mouth?
- She is good at painting
3. after certain verbs: like, hate, admit, imagine
4.in compound nouns:
- a driving lesson,
- a swimming pool,
- bird-watching,
- train-spotting