Spelling Rules: --ing / --ed

http://www.grammar.cl/Notes/Spelling_ING.htm


http://www.oxforddictionaries.com/words/verb-tenses-adding-ed-and-ing


------------------------------- Rules for Adding ING to Verbs -------------------------------

The following is a guide to the correct spelling of –ing forms of verbs and gerunds.
The general rule when changing a verb into its -ING form is just to add -ING to the end of the verb.

Infinitive	ING form
to feel	feeling
to go	going
to work	working
to sleep	sleeping

• She wasn't feeling very well.
• He is working on a new project.
• The children are sleeping so be quiet.

Spelling exceptions

The following exceptions exist when spelling words ending in ING:
1). If the verb ends in an E we remove the E and add ING.

Infinitive	ING form
to live	living
to have	having
to make	making
to take	taking

• People are living longer now than they were 100 years ago.
• We are making a chocolate cake.
• He was taking his time to get ready.

2). If the verb ends in a consonant + vowel + consonant, we double the final consonant and add ING.

Infinitive	ING form
to stop	stopping
to sit	sitting
to plan	planning
to get	getting
to swim	swimming

• The policeman is stopping the traffic.
• We are planning a surprise party for our teacher.
• I think I am getting a cold.

3). If a two-syllable verb ends in a consonant + vowel + consonant, we do not double the final consonant when the stress is on the first syllable.

Infinitive	ING form
to happen	happening
to enter	entering
to offer	offering
to suffer	suffering

• What is happening?
• They are offering a discount.
• Many people are suffering from a lack of food and water.

4). But, we do not double the final consonant when the verb ends in W, X or Y or when the final syllable is not emphasized.

Infinitive	ING form
to fix	fixing
to enjoy	enjoying
to snow	snowing

• He fixing his bike.
• We are enjoying this great weather.
• It's snowing outside.

5). If the verb ends in IE we change it to YING.

Infinitive	ING form
to lie	lying
to die	dying
to tie	tying

• I know you are lying to me!
• You should water your plant more because I think it is dying.
• The little boy is tying his shoelaces.

6). If the verb ends in consonant + vowel + L, we normally double the final L and add ING.
Note: In the United States (US) they do not double the L when the accent is on the first syllable.

Infinitive	ING form (UK)	ING form (US)
to travel	travelling	traveling
to marvel	marvelling	marveling

• I have been travelling around South America for 6 months.
• He was marvelling at her beauty.

7). If the verb ends in a stressed vowel + R, we double the final R and add ING.

Infinitive	ING form
refer	referring
defer	deferring

• Are you referring to this one or that one?
• They are thinking of deferring payment of their mortgage.

8). If the verb ends in an unstressed vowel + R, we do not double the final R and add ING.

Infinitive	ING form
to offer	offering
to suffer	suffering
to whisper	whispering

• I am offering you a special deal.
• He is now suffering the consequences of his actions.
• I wonder what he is whispering in her ear.