Final consonant doubling in English

As you surely know, the final consonant of some verbs gets doubled when the suffix -ing or -ed is added, e.g.

In other cases, it is not doubled:

The rule governing the doubling of the final consonant is actually quite simple. If a verb has just one syllable and ends with exactly one vowel followed by one consonant (except “w”, “x”, and “y”, which we will explain below), the consonant is doubled:

If there are two vowels or two consonants at the end, no doubling occurs:

This applies also to “oo” and “ee”:

Similarly, if a verb ends with a silent “e”, do not double the preceding consonant:

The letters “w” and “y” are never doubled (they act as vowels in this context, pronounced /ʊ/ and /ɪ/, respectively):

Similarly, the letter “x” is never doubled, because it represents two consonants “ks”:

Words beginning with “qu” may seem like an exception to the rule, but “qu” is actually pronounced as “kw”, i.e. as two consonants, which does not prevent the following vowel from doubling:

The rule can be summarized as:

How does the rule apply to polysyllabic words? I will describe all the details in another article. In the meantime, you can check out my book, which describes all the rules and exceptions.