*Excerpt from the forthcoming grammar book Practical English: Theory and Exercises, Book 2. For Practical English: Theory and Exercises, Book 1, go to Publications
A verb ending in -ing is either a present participle or a gerund. The two forms look identical, but they have different functions in a sentence.
Mini-glossary of spelling terminology
Ending = a small particle of a letter or more that is added to the end of a word.
Vb-s
Vb-es
Vb-ing
Letter = a symbol used in writing a language as a correspondent of a sound in the respective language
letters N, n
Consonant sound = a sound pronounced without letting the air flow freely through the mouth
sounds /b/, /g/, /l/, /p/, /s/
Vowel sound = a sound pronounced by letting the air flow freely through the mouth
sounds /ɑ:/, /e/, /ɔ:/
Consonant (letter) = the letter corresponding to a consonant sound
letters b, g, l, p, s
Vowel (letter) = the letter corresponding to a vowel sound
letters a, e, i, o, u
Syllable = one unit of speech usually containing a vowel sound
syll-a-ble (the word syllable has three syllables)
Monosyllabic word = a word that consists of one syllable
stop
Disyllabic word = a verb/word that consists of two syllables
en-gage
Trisyllabic word = a word that consists of three syllables; some dictionaries consider three-syllable words as polysyllabic
con-sid-er
Polysyllabic word = a word that consists of three or more syllables
re-con-si-der
Derivative = a word form made from another word form
the verb overtax is a derivative of the verb tax
the noun applicability is a derivative of the adjective applicable
Stress/Accent = the pronunciation of a syllable or two syllables with greater force than the other syllables in the same word
cover
attract
Stress mark = a specific symbol such as a small vertical line that is placed before the stressed syllable of a word
cover /'kʌvə(r)/
Stressed syllable = the syllable that carries the most stress or the second most stress in a word
Primary stress = the most stress in a word
Primary stress mark = a specific symbol such as a small vertical line that is placed above the line of print and before the syllable that carries the most stress
attract /ə'trækt/
Secondary stress = the second most stress in the word
disrespect
Secondary stress mark = a specific symbol such as a small vertical line that is placed below the line of print and before the syllable that carries the second most stress
disrespect / ̦dısrı'spekt/
Precede = a word or letter going before another word or letter
come -> consonant letter m is preceded by the vowel letter o
Listen to the counsel of your lawyer! -> noun counsel is preceded by definite article the
The following are the spelling rules of the -ing form of the English verbs.
Note:
a. The verbs listed below can have more meanings than the ones written in the tables.
b. For checking all the meanings of the verbs listed below, see a good dictionary.
Rule 1
Verbal endings usually alter the basic form Vb1.
write -> writing
decide -> deciding
Rule 2
When regular and irregular verbs (Vb1) end in silent -e, we drop the final -e before adding -ing.
Vb-ɇ + -ing => Vb-ing
Exception
There are some verbs that do not obey Rule 2.
Vb-e + -ing => Vb-eing
Rule 3
When regular and irregular verbs (Vb1) end in -ee, we simply add -ing to their basic form.
Vb-ee + -ing => Vb-eeing
Rule 4
When regular and irregular verbs (Vb1) end in -ie, we change -ie to -y before adding -ing.
Vb-ie + -ing => Vb-ying
Rule 5
When regular and irregular verbs (Vb1) end in -ic, we change -ic to -ick before adding -ing.
Vb-ic + -ing => Vb-icking
Rule 6
When monosyllabic verbs (Vb1) end in a consonant preceded by one single vowel we double the final consonant before adding -ing.
Exception
There are some verbs that do not obey Rule 6.
Rule 7
When monosyllabic verbs (Vb1) or derivatives of monosyllabic verbs end in -w or -x preceded by one single vowel, we simply add -ing to their basic form, without any change.
Vb-x + -ing -> Vb-xing
Vb-w + -ing -> Vb -wing
Rule 8
When verbs (Vb1) are disyllabic or polysyllabic, with their last syllable stressed and their final consonant preceded by one single vowel, we double their final consonant before adding -ing.
Exception
When some regular verbs are disyllabic or polysyllabic, with their first syllable stressed and their final consonant preceded by one single vowel, we double their final consonant before -ing.
Rule 9
When regular verbs (Vb1) end in -l preceded by one single vowel or two vowels pronounced separately, we double final -l before -ing.
Vb-l + -ing => Vb-lling
Exception
a. In American English, when regular verbs (Vb1) end in -ll preceded by one single vowel, we keep final -ll before -ing.
Vb-ll + -ing => Vb-lling
b. In American English, when regular verbs (Vb1) end in -l preceded by one single vowel or two vowels pronounced separately, we do not double final -l before -ing.
Vb-l + -ing => Vb-ling
c. In American English, when some regular verbs (Vb1) have their last syllable stressed, we double final -l before -ing. (see Rule 8)
Rule 10
When verbs (Vb1) end in -y, we simply add -ing to their basic form.
Vb-y + -ing => Vb-ying
Rule 11
When verbs (Vb1) do not fall under any of the above-mentioned rules, we simply add -ing to their basic form.
Vb + -ing => Vb-ing