Rule VI: cons x2 (double consonants)

	VI.	Abbreviation:	cons x2 and (c, ck)
		Description:	Consonant doubling
		Example verb:	7.	to permit
		Application:

General rule if a verb ends on vocal + consonant and if the verb has only one vocal then the final consonant is doubled (e.g. "to shop" => "shopped / shopping", "to get" => "getting") "y" counts as a vocal here Restriction to the general rule excepted from this general rule are the final consonants "w", "x" and "y" (e.g. "to show" => "showed / showing", not "showwed / showwing") excluded as well are all verbs that have a double vocal before the final consonant (e.g. "to read" => "reading" or "to book" => "booking" and not "readding" or "bookking") Further rules for consonant doubling if the final consonant is a "c", then this consonant does not get doubled but is replaced with "ck" (e.g. "to frolic" => "frolicked") if the final consonant is an "l", then in case of British English this consonant will always be doubled (e.g. "to signal" => "signalling"). All now remaining verbs do only double their final consonant if the respective verb is stored in the list of verbs with consonant doubling.

		Validity:	Present:	-
			Past:	all forms
			Imperative:	-
			Present Participle:	always
			Past Participle:	always

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also see:

Verb-irregularities - overview