An ELT Glossary : Participle Forms / Gerunds

English has two participle forms - the so called "present" and "past" participles. However, as we will see below, these names are misleading and the forms actually have no conection with tense or time.

1. The "present" participle 

a) Form :  the base form of the verb plus -ing : go, going. Spelling changes may occur : a verb ending in a consonant plus "e" in the written form  will drop the "e" in the participle form (make, making; arrive, arriving) while a verb ending with a short vowel plus consonant sound will double the consonant before -ing : shut, shutting; skim, skimming.

b) Use : The "present" participle has three main uses :

i) It is used, together with the auxiliary verb BE, in verb forms with progressive aspect : She is going / she was going / she has been going etc. Notice that there is nothing "present" about it. The verb form expresses whatever time is indicated by the form of the verb BE.

ii) It can be used to introduce a subordinate clause : 
Walking down the road, John saw a house for sale.
Nestling on the cliffs, the hotel has a perfect view of the sea.
Again, notice that there is nothing "present" involved in the verb. it is non-finite (ie it has no subject and is not marked for tense, person number etc) and it is only by reference to the verb in the main clause that we become aware what the subject is, and what the time of the event is - and this (as in the first example) may be any time - not necessarily "present".

iii) It can be used as an adjective : hot, running water; an interesting book. Again, the concept of "present" makes no sense here.

2.  The "past" participle

a) Form : The "past" participle may be regular or irregular. The regular form adds -ed to the base form of the verb ( eg play- played) though this is again subject to spelling changes : a verb ending in consonant plus "y" in the written form will change the "y" to "i" - study-studied; while, again, a verb ending with a short vowel plus consonant sound will double the consonant before the -ed (eg: knit - knitted). Irregular forms include eg show - shown; run-run; build-built

b) Use:  The past participle can be used...

i) ... together with the auxiliary verb HAVE to form verbs with perfect aspect  : I've seen; I'd known

ii) together with the auxiliary verb BE to form verbs in the passive voice : It is located; It was expected.

iii) and iv)  as with the present participle, to introduce a subordinate clause :
Located on the cliff, the hotal has a perfect view of the sea.
Written by a specialist in the field, the book sold out on its first day.
or as an adjective : a broken promise; a used car.

Again, notice that the participle used as a verb is always non-finite and in none of these uses is there any necessary connection with the past - this is made apparent by the finite verbs in the sentence and the context. For example we understand that the hotel is located on the cliffs - ie the participle describes a present situation.

3. The Gerund (or Gerundive)

To make the terminology confusion worse, the V+ing form is given another name for a further use : it may be used as a noun and is then known as the gerund. For example :
i) Swimming is Janet's main hobby (used as subject of the verb)
ii) I like reading  (used as object of the verb)

Notice that in these positions, as it is acting as subject or object, it could be replaced by a noun or pronoun :
i) Football/It is Janet's main hobby.
ii) I like dogs / them.

For some great teaching ideas...

Gerngross, Puchta and Thornbury, Teaching Grammar Creatively, CUP

(Remember that Amazon often has both new and used copies of the books you want at prices lower than those advertised here. It's always worth checking it out.)