(Consult a textbook or a grammar for complete rules and lists of exceptions)
For more mnemonic devices (including vocabulary) please take a look at:
Mnemonic Latin. Mnemonic hints for learning Latin vocabulary and grammar.
Nouns that are singular only:
Argentum, aurum, ferrum, plebs, justitia,
Ver, aevum, letum, sanguis, pueritia.
Nouns that are Plural only:
Manes, liberi, Penates,
Divitiae, cunae, nugae, grates,
With arma, munia, magalia,
And festive seasons, as Floralia.
Nouns of Common Gender
Common are to either sex:
Artifex and opifex,
Conviva, vates, advena,
Testis, civis, incola,
Parens, sacerdos, custos, vindex,
Adolescens, infans, index.
Judex, heres, comes, dux,
Princeps, municeps, conjux,
Obses, ales, interpres,
Auctor, exul; and with these
Bos, dama, talpa, tigris, grus,
Cavis and anguis, serpens, sus.
Gender in I Declension
Nouns denoting males in a
Are by meaning Mascula;
And added to the Males must be
Hadria, the Hadriatic Sea.
Feminina stand in us,
Alvus, arctus, carbasus,
Colus, humus, pampinus,
Vannus; names of Plants, as pirus;
Names of Jewels, as sapphires.
Neuter, pelagus and virus.
Vulgus Neuter commonly,
Rarely Masculine, we see.
Gender in III Declension
Substantives in do and go
Genus Femininum show.
But ligo, ordo, praedo, cardo,
Are Mascula; and Common margo.
Verbal Nouns in io call
Feminina, one and all:
Mascula will only be
Things that you may touch or see,
(As curculio, vespertilio,
Pugio, scipio, and papilio,)
With the Nouns that number show,
Such as ternio, senio.
Echo Femininum name:
Caro (carnis) is the same.
Femininum call arbor;
Neuter aequor, marmor, cor.
Of the Substantives in os,
Feminina cos and dos:
While, of Latin Nouns, alone
Neuter are os (ossis), bone,
And os (oris), mouth: a few
Greek in os are Neuter too.
Many Neuters end in er,
Siler, acer, verber, ver,
Tuber, uber, and cadaver,
Piper, iter, and papaver.
Feminina, compes, teges,
Merces, merges, quies, seges,
Through their Genitives increase,
With the Neuters reckon aes.
Many Nouns in is we find
To the Mascula assigned:
Amnis, axis, caulis, collies,
Clunis, crinis, fascis, follies,
Fustis, ignis, orbis, ensis,
Panis, pascis, postis, mensis,
Torris, unguis, and canalis,
Vectis, vermis, and natalis,
Lapis, sanguis, cucumis,
Pulvis, cases, Manes, glis.
Chiefly Mascula we view,
Sometimes Feminina too,
Callis, sentis, funis, finis,
Torquis, and, in poets, cinis.
Mascula are adamas,
Elephas, mas, gigas, as:
Vas (vadis) too as Male is known,
Vas (vasis) as a Neuter Noun.
Most are Mascula in ex:
Feminina, forex, lex,
Nex, supplex: Common, pumex,
Imbrex, obex, silex, rumex.
Mascula appear in ix,
Fornix, phonix, and calyx
Mascula are fons and mons,
Chalybs, hydrops, gryps, and pons,
Rudens, torrens, dens and cliens,
Fractions of the as, as triens;
Add to Mascula tridens,
Occidens and oriens,
Bidens (hoc): but bidens (sheep)
With the Feminina keep.
Mascula are found in es
Verres and acinaces.
Mascula are found in
Furfur, turtur, vultur, fur.
Feminina, some in us
Keep u long, as, servitus,
With juventus, virtus, salus,
Senectus, tellus, incus, palus.
Also pecus (pecudis)
Of the Female gender is.
Mascula are found in us
Lepus (leporis) and mus.
Mascula in l are mugil,
Consul, sal and sol, with pugil.
Mascula are ren and splen,
Pecten, delphin, attagen.
Feminina some in on;
Gorgon, sindon, halcyon.
Gender in IV Declension
Feminina, trees in us,
With tribus, acus, porticus,
Domus, nurus, socrus, anus,
Idus (iduum) and manus.