[c] 2. Both methods of formation exist together in Hebrew. The internal mode of formation by means of vowel changes is tolerably extensive (קָטַל, קָטֵל, קָטֹל; קִטֵּל, קֻטַּל, &c.). This is accompanied in numerous cases by external formation also (הִתְקַטֵּל, הִקְטִיל, נִקְטַל, &c.), and even these formative additions again are subject to internal change, e.g. הָתְקַטַּל, הָקְטַל. The addition of formative syllables occurs, as in almost all languages, chiefly in the formation of the persons of the verb, where the meaning of the affixed syllables is for the most part still perfectly clear (see §§ 44, 47). It is also employed to distinguish gender and number in the verb and noun. Of case-endings, on the contrary, only scanty traces remain in Hebrew (see § 90).
