What the plural does

Why that ending: neuter, and neuters split between -e and -uri. This one takes -e — stored, not derived.

Why the stem holds: an ending only reaches back when it meets a stressed o or e (mechanism B/C). This stem has au, a diphthong that does not alternate.

⚠️ You read this one as masculine and produced doi scani. The singular cannot tell you — un covers masculine and neuter. Only două scaune proves it. Latin scamnum; RU скамейка is the same family.

Why that ending: the second neuter plural, and the most informative ending in the whole system — at this level a plural in -uri means neuter; the few feminine ones (vremuri "times", treburi "chores") arrive later. It descends from the Latin neuter plural in -ora (corpus → corpora → RO corp → corpuri), which Romanian then spread far beyond its original words.

Why nothing else moves: -uri begins with u, and u triggers no stem alternation at all. Words in this class are the safest in the unit.

⚠️ UA час means time — Romanian ceas is the object. Time is timp, which you already have. The initial ce- is the U01 digraph: [tʃas], never [tse-].

Why that ending: same class as ceas and timp — short, consonant-final neuters cluster here. No hook for the word itself; memorize it flat. The plural is what tells you the gender.

Note the t: it stays t. The t → ț shift fires only before -i, and this word never sees one. Compare student → studenți.

Why the singular ends in -u at all: it is the Latin neuter ending -um worn down — lucrum "gain". A final -u is a strong bet for neuter, not a law: membru (member) and codru (forest) are masculine, and U08 brings metru (metre) and litru (litre), masculine too.

⚠️ You took it as feminine on first contact. Feminine is -ă. -u is neuter. Hook: same root as a lucra, to work.

Why the a holds: Latin casa had a genuine a — there is no older vowel underneath for the front ending to pull up. Maps directly to Latin casa.

This is the control case. Put it against masă → mese below: same shape, same ending, opposite behaviour. That pair is the reason a Romanian noun is stored as word + gender + plural.

Why nothing shifts: the a in camer- is a genuine a (Latin camera, from Greek kamára "vault"), exactly like casă. Same for adresă → adrese, vârstă → vârste, sută → sute.

⚠️ English false friend: a camera is un aparat foto. UA камера half-helps — take it in the sense of chamber.

Why the -i plural and not the -e one: feminine has two plural endings and this one is stored. There is no rule to recover it from the singular — ușă and casă look identical and go different ways. Same class: limbă → limbi (language → languages), lună → luni (month → months; also moon).

Listen to the syllables. ușă is two — u-șă. uși is one: the -i is not a vowel, so the plural loses a syllable instead of keeping it. That never happens with casă → case, where a vowel is swapped for a vowel.

Why the diphthong appears: mechanism B. In the singular the stressed o is the last vowel of the word — nothing follows it, so it stays plain. The plural adds -e, and oa is exactly what a stressed o becomes when a, ă or e follows. The ending did not change the stem out of spite — it supplied the trigger the singular was missing.

Same event, already in your ledger: telefon → telefoane. And running the other way, when the plural ending is -i: floare → flori.

⚠️ English is the decoy here: calculator means computer, not a pocket calculator. You produced doi calculatori — the -i plural is masculine, and this word is neuter.

Identical to calculator — stressed o at the end of the singular, -e arrives, diphthong opens. Two syllables become three: cre-ion → crei-oa-ne.

Hook: French crayon, and English borrowed the same word. Romanian took it from French in the 1800s, which is why it looks nothing like Latin.

Why it flattens — and why this is not the masă problem: the base vowel here is plain e, visible in Latin fenestra. The singular's -ă triggers e → ea. The plural's -e does not, because ea is only allowed before a and ă. Remove the trigger, and the diphthong goes.

This one is fully predictable. Once you know the base vowel is e, both forms follow from the rule. That is the difference between mechanism C and mechanism D — and it is why masă gets its own group.

⚠️ You called it neuter despite the -ă. Gate 1 of the gender gate: -ă → feminine, stop — never ask "is it an object?" about a word ending in -ă. Hook: EN defenestration, throwing someone out of a window.

Why: Latin mensa. The base vowel was always e, and it survives untouched in the plural. What changed is the singular: mensa → measă → masă — after a labial (m, f, v, p), ea dropped all the way down to a centuries ago (the same change gives feată → fată, girl). So this is mechanism C with the footprint erased — the same event as fereastră, one step further along.

Why you still have to store it: modern spelling shows you m-a-s-ă and c-a-s-ă, and they are indistinguishable. Nobody can read the Latin vowel off the page.

⚠️ You produced mase — the ending fired, the stem shift did not. This is the single word in the fourteen where the plural has to be memorized as a whole form. Hook: EN the officers' mess, the table they eat at.

Why the consonant moves: mechanism E — -i is the only ending that reaches back to consonants, and t is on its list. Identical to student → studenți, and to UA рука → руці.

Both syllable counts are three — pe-re-te, pe-re-ți. The final -i is not a vowel; it is the softness you already own from день, кінь.

⚠️ Masculine despite the -e ending, which normally reads feminine. This is the exception the gender test warns about (carte and cheie are the feminine norm). You also read the singular as a plural — un perete is one wall.

What actually happens: the stem already ends in the glide [j]. che-ie is [ˈke-je], two syllables. The plural swaps the final -e for -i, the two i sounds collapse into one, and chei comes out as a single syllable [kej].

Why ch and not c: the h is a blocker, not a sound. A plain c before e/i would give [tʃ] — chei would be «чей». The h holds the [k] hard. Same job it does in ochi.

Hook: Latin clavis. Romanian systematically turns Latin cl- into ch- — the same change gives you clamare → a chema, to call.

Why the plural is invisible: the masculine plural is -i, and this stem already ends in exactly that non-syllabic -i — inherited from Latin oculus → *oclu → ochi. The ending has nowhere to land. Identical on the page and identical in the ear: [okʲ], one syllable, both numbers.

The h again: without it, oci would be [otʃ]. Spelled ch, it stays a hard [k] with a soft breath after it — Ukrainian's -кь.

⚠️ Masculine, and it is an object — one of the two words in this unit (with perete) that no gate settles. And there is no body-part gender system to lean on: mână (hand) is feminine, picior (leg) is neuter, ochi is masculine. Stored — no rule reaches it. Hook: EN ocular.