-as

The Esperanto suffixes -as, -is, -os, -us are related, and appear to have been inspired by previous language projects:

This play of vowels is not an original idea of Zamenhof's: -as, -is, -os are found for the three tenses of the infinitive in Faiguet's system of 1765; -a, -i, -o without a consonant are used like Z's -as, -is, -os by Rudelle (1858); Courtonne in 1885 had -am, -im, -om in the same values, and the similarity with Esperanto is here even more perfect than in the other projects, as -um corresponds to Z's -us. —An International Language (1928)

The vowel of -as is likely cognate with the Latin present, as in amat (“s/he loves”), and the corresponding present infinitive amāre, permitting the natural (for a European) -ant ending. i could come from past tense in Latin ami, amisti.

-as

1. ending of the present tense in verbs.

• IPA^(key): [ɒʃ]

-as

1. (adjective-forming suffix) Added to a noun to form an adjective meaning "having something, a quality".

   ‎haj (“hair”) + ‎-as → ‎hajas (“covered with hair”)

2. (noun-forming suffix) Added to a noun to form an occupation or a collective noun.

   ‎fazék (“pot”) + ‎-as → ‎fazekas (“potter”)

3. (number-forming suffix) Added to an ordinal number to form a digit or figure, cf. the relevant template.

   ‎három (“three”) + ‎-as → ‎hármas (“the digit or figure 3”)

• (all senses) Harmonic variants:

  -s is added to words ending in a vowel. Final -a changes to -á-. Final -e changes to -é-.

  -os is added to some back vowel words ending in a consonant

  -as is added to other back vowel words ending in a consonant

  -es is added to unrounded front vowel words ending in a consonant

  -ös is added to rounded front vowel words ending in a consonant

• Appendix:Hungarian suffixes

Borrowed from Esperanto -as, Latin -ās, French -es, Spanish -as.

-as

1. desinence of the present tense in verbs

• -is
• -os
• -ar
• -ir
• -or

• -eas (after palatal consonants)

From Old Irish -as, from Proto-Celtic *-assus, from Proto-Indo-European *-ad-tus.

-as m

1. Nominal suffix, used to form abstract ideas or nouns

   Synonym: -achas

• (Classical) IPA^(key): /aːs/

A declined form of -us (suffix forming adjectives).

-ās

1. accusative feminine plural of -us

A conjugated form of -ō (suffix forming first-conjugation verbs).

-ās

1. second-person singular present active indicative of -ō

A declined form of -a (suffix forming masculine agent nouns).

-ās m

1. accusative plural of -a

-as m

1. nominal suffix (ending) of the first declension of the nouns.
2. nominal suffix (ending) which indicates a demonym.

   ‎Rusija (“Russia”) + ‎-as → ‎rusas (“Russian (person)”)

-as

1. Alternative form of -yssh

• “-ish, (suf.)” in MED Online, Ann Arbor, Mich.: University of Michigan, 2007, retrieved 16 June 2018.

-as

1. Alternative form of -esse

• “-esse, (suf.)” in MED Online, Ann Arbor, Mich.: University of Michigan, 2007, retrieved 24 June 2018.

From Proto-Samic *-ës.

-as

1. Forms nouns from verbs, indicating something used for performing the verb.

   ‎vuoidat (“to smear”) + ‎-as → ‎vuoiddas (“ointment”)

This suffix triggers the weak grade on a preceding stressed syllable in the nominative singular and essive, and the strong grade in the other forms.

Perhaps from the Proto-Germanic accusative plural ending *-anz, with regularly lost -n- before a fricative, or perhaps from the nominative plural *-ōs, a voiceless variety of the regular ending *-ōz, or a merger of both. Akin to Saterland Frisian -s, West Frisian -s, Old Saxon -os (Low German -s), Dutch -s, Swedish -ar.

-as

1. Plural ending of nominative and accusative cases, originally of a-stem masculine nouns, later extended to other nouns.

• Middle English: -æs, -es, -s
  • English: -es, -s
  • Scots: -is, -es, -s

• -es (after palatal consonants)
• -us

From Proto-Celtic *-assus, from Proto-Indo-European *-ad-tus.

-as m

1. Nominal suffix, used to form abstract ideas or nouns

   ‎óclach (“young man”) + ‎-as → ‎óclachas (“youth”)

   ‎muinter (“family”) + ‎-as → ‎muinteras (“familiarity”)

• Rudolf Thurneysen (1940) A Grammar of Old Irish, Dublin Institute for Advanced Studies, § 261

• IPA^(key): /as/

-as m pers

1. masculine noun suffix

-as

1. forms the second-person singular present indicative of 1^st conjugation verbs

   ‎falar (“to speak”) + ‎-as → ‎falas (“you speak”)

2. forms the second-person singular subjunctive present of 2^nd and 3^rd conjugation verbs

   ‎correr (“to run”) + ‎-as → ‎corras (“that you run”)

3. forms the second-person singular negative imperative of 2^nd and 3^rd conjugation verbs

   ‎correr (“to run”) + ‎-as → ‎não corras (“don’t run”)

From Latin -ās, the second-person singular present active indicative ending of first conjugation verbs.

-as

1. suffix indicating the second-person singular present indicative of -ar.

From Latin -eās, Latin -ās, and Latin -iās, the second-person singular present active subjunctive endings of second, third, and fourth conjugation verbs, respectively.

-as

1. suffix indicating the second-person singular present subjunctive of -er verbs and -ir verbs

• -es