-ing

-ing is a suffix used to make one of the inflected forms of English verbs. This verb form is used as a present participle, as a gerund, and sometimes as an independent noun or adjective. The suffix is also found in certain fossilized words like morning and ceiling, and in names such as Browning.

The Modern English -ing ending, which is used to form both gerunds and present participles of verbs (i.e. in noun and adjective uses), derives from two different historical suffixes.

The gerund (noun) use comes from Middle English -ing, which is from Old English -ing, -ung (suffixes forming nouns from verbs). These in turn are from Proto-Germanic *-inga-, *-unga-,*-ingō, *-ungō, which derives from Proto-Indo-European *-enkw-. This use of English -ing is thus cognate with the -ing suffix of Dutch, West Frisian, and the North Germanic languages, and with German -ung.

The -ing of Modern English in its participial (adjectival) use comes from Middle English -inge, -ynge, alterations of earlier -inde, -ende, -and, from the Old English present participle ending -ende. This is from Proto-Germanic *-andz, from the Proto-Indo-European *-nt-. This use of English -ing is cognate with Dutch and German -end, Swedish -ande, -ende, Latin -ans, -ant-, Ancient Greek -ον (-on), and Sanskrit -ant. -inde, -ende, -and later merged with the noun and gerund suffix -ing , perhaps because the French speaking elites naturally confused them as there was only one French equivalent to both (compare the Modern French participial, noun and gerund suffix -ant). Its remnants, however, are still retained in a few verb-derived words such as friend, fiend, errand, thousand, bond, etc.

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