Appended to nouns and adjectives to form adjectives, represents the Old English -lῑc, corresponding to Old Frisian, Old Saxon -lîk (Dutch -lijk), Old High German -lîk (Middle High German -lîch, modern German -lich), Old Norse -lig-r, -leg-r (Swedish, Danish -lig), Gothic -leik-s:—Germanic -lîko-. The phonology of the Old English form, as also of the modern German and the Old Norse forms, is somewhat abnormal, the frequency in use of the suffix having caused loss of the original secondary stress, with consequent shortening of the vowel, and in Old Norse also voicing of the guttural. A further irregularity appears in the phonetic development in Middle English The normal representation of Old English -lic was -lik in northern dialects and -lich in southern dialects. These forms are found as late as the 15th century; but the form -li, -ly, which (though parallel with the reduction of Old English ic to I, and of Middle English everich to every) seems to be chiefly due to the influence of the Scandinavian -lig-, occurs in northern and midland dialects as early as the 13th cent., and before the end of the 15th cent. had become universal. In the Ormulum (c1200) -lic (rarely -like) is used before a vowel and at the end of a line, and -liȝ before a consonant; the inflected form -like (disyllabic) seems often to be used, for metrical reasons, where grammar would require the uninflected form. In the comparative and superlative (Old English -licra, -e, -licost) the Middle English form had regularly -k according to phonetic law in all dialects (in the south the usual 13–14th century form was -lukere, -lokere); but where the positive had the form -li new comparatives and superlatives in -lier, liest were regularly formed from it. The original Germanic adjectives in -lîko- were compounds of the noun *lîkom appearance, form, body (see lich n.). Thus *mannlîko- (‘manly’) means etymologically ‘having the appearance or form of a man’; gôðolîko- (‘goodly’) ‘having a good appearance or form’, or ‘having the appearance or form of what is good’. The primitive force of the suffix may therefore be rendered by ‘having the appearance or form indicated by the first element of the word’; but while in the historical Germanic languages it has remained capable of expressing this meaning, it has in all of them acquired a much wider application.When appended to nouns, the most general senses of the suffix in all Germanic languages are ‘having the qualities appropriate to’, ‘characteristic of’, ‘befitting’. In English of all periods it has been a prolific formative; the adjectives formed with it are most frequently eulogistic, as in kingly, knightly, masterly, princely, queenly, scholarly, soldierly (cf. manly adj., womanly adj. with mannish, womanish); among the examples with dyslogistic sense are beastly, beggarly, cowardly, dastardly, rascally, ruffianly, scoundrelly. In Old English, as in other Germanic languages, the suffix had often the sense ‘of or pertaining to’; but the adjectives have, so far as this meaning is concerned, been to a great extent superseded by synonyms of Latin or Romanic etymology. Thus manly formerly admitted of the senses now expressed by human and masculine; for one of the older senses of timely we must now say temporal. Another use of the suffix, common to English with other Germanic languages, is to form adjectives denoting periodic recurrence, as daily, hourly, monthly, nightly, weekly, yearly.When -ly is appended to an adjective, the resulting derivative adjective often connotes a quality related to or resembling that expressed by its primary; cf., e.g., Old English léof ‘dear’ with léoflic ‘lovely’ (or, as it might be rendered, ‘such as becomes dear’). The diminutive sense found in modern German gelblich yellowish, süsslich sweetish, though a very easy development from the original sense of the suffix, does not seem ever to have existed in English. Even in Old English -lic had apparently ceased to be used in new formations from adjectives; the new adjectives < adjective + -ly suffix¹ that have arisen in Middle English or in modern English seem to be from the adverbs.

Forming adverbs. The form-history of the suffix in English is similar to that of -ly suffix¹: in Middle English the Old English -líce was normally represented by -līche (southern), -līke (northern), the comparative being -lῑker, -luker, -loker (superlative -est).The form -li, -ly, which was current in East Midland English in the 14th cent., and became general in the 15th cent., is probably due to the influence of the Old Norse -liga. In the strongly Scandinavianized dialect of the Ormulum (c1200) -lig and -like are used indifferently, according to the requirements of the metre. Where the positive ended in -li, -ly, the comparative and superlative ended in -lier, -liest. In the 15–17th century forms like falslyer, traitorouslyer (Malory), softlier, justlier, widelier (Long Barclay's Argenis 1625), easilier, -est (R. Baxter Saving Faith 1658) were common, but in later use the adverbs in -ly are compared with more, most, the inflectional forms being only employed in poetry or for rhetorical effect.In Germanic an adverb with this suffix must have implied the existence of an adjective with the suffix corresponding to -ly suffix¹. In Old English, however, there are several instances (e.g. bealdlíce boldly, swétlíce sweetly) in which an adverb in -líce has been formed directly from a simple adjective without the intervention of an adjective in -lic. In Middle English the number of these direct formations was greatly increased, and when the final -e, which was the original Old English adverb-making suffix, ceased to be pronounced, it became usual to append -ly to an adjective as the regular mode of forming an adverb of manner. It was, down to the 17th cent., somewhat frequently attached, with this function, even to adjectives in -ly, as earlily, godlily, kindlily, livelily, lovelily, statelily; but these formations are now generally avoided as awkward, while on the other hand it is felt to be ungraceful to use words like godly, goodly, lovely, mannerly, timely, as adverbs; the difficulty is usually evaded by recourse to some periphrastic form of expression. In examples belonging to the 16th and 17th centuries it is sometimes difficult to determine whether a writer intended the adverb goodly to mean ‘in a good manner’ or ‘in a goodly manner’, and there are other instances of similar ambiguity. In the words denoting periodical recurrence, as daily, hourly, the adjective and the adverb are now identical in form. A solitary example of an adverb < noun + -ly suffix² with no related adjective is partly. From the early part of the 16th cent. the suffix has been added to ordinal numerals to form adverbs denoting serial position, as firstly, secondly, thirdly, etc. (cf. French premièrement, etc.).When -ly is attached to a disyllabic or polysyllabic adjective in -le, the word is contracted, as in ably, doubly, singly, simply; contractions of this kind occur already in the 14th cent., but examples of the uncontracted forms (e.g. doublely) are found as late as the 17th cent. Whole + -ly suffix² becomes wholly, but in all other similar instances the written e is retained before the suffix, e.g. in palely, vilely, puerilely. Adjectives ending graphically with ll lose one l before -ly, as in fully (in southern English commonly pronounced with a single l, but in Scotland often with double or long l), dully , , coolly , . Adjectives of more than one syllable ending in y change y to i before -ly, as in merrily; in formations from monosyllabic adjectives the usage varies, e.g. dryly, drily; gayly, gaily (cf. daily adj., which is the only current form); slyly, slily (but always shyly); greyly, grayly has always y. Another orthographical point is the dropping of the e in the two words duly, truly. It is unusual to append -ly to an adjective in -ic; the ending of the adverb is nearly always -ically suffix, even when the only current form of the adjective ends in -ic.