Stem Changes: גדול → גדולה, יפה → יפים

The three endings that make an adjective agree — ־ָה, ־ִים, ־וֹת — are set out on adjective endings. This page is about what happens at the other end of the word while they attach. Hebrew endings are stressed, and a stressed ending pulls the vowels in front of it out of shape: the feminine of גָּדוֹל gadól is not gadolá but גְּדוֹלָה gdolá, with the first vowel gone. Three classes do three different things here, and only one of them is visible in unpointed writing.

The stem in front of the ending gives way

Take the largest and dullest class: adjectives with a long o or u in the second syllable. The ending goes on, the stress moves onto it, and the vowel two syllables back is squeezed out.

Two things to notice. The o or u never budges — it is a long vowel and it survives everything. And the vowel that vanishes leaves a shva behind, which in Israeli speech is simply nothing: gdolá, krovím, with a consonant cluster at the front of the word. עצוב looks different only because its first letter is a guttural, and a guttural will not sit under a bare shva: it takes a chataf instead, which keeps a small a audible — עֲצוּבָה atsuvá. That happens wherever א, ה, ח or ע opens the word, so חָדָשׁ gives חֲדָשָׁה and אָרוֹךְ, in the next section, gives אֲרוּכָּה.

אָרוֹךְ, where the vowel changes as well as moving

One very common member of that class does something extra, and learners mispronounce it for years. אָרוֹךְ arókh "long" has a cholam in the masculine and a shuruk everywhere else — and the final כ, spirant in arókh, takes a dagesh and hardens to k:

The spelling is identical in all four — ו for both vowels, and ktiv male writes no dagesh — so nothing on the page tells you that the masculine ends in -kh and the feminine in -k. This one is memorised, not derived.

The ־ֶה class: the ending is replaced, not added

A large group of adjectives already ends in a vowel in the masculine singular — יָפֶה, קָשֶׁה, רָזֶה, שָׁוֶוה. Here the ending does not stack on top: the final ־ֶה is what gets replaced, and the stem in front of it does not move at all.

Look at the middle column. The two singulars are the same three letters. Only the vowel differs, and unpointed Hebrew does not write vowels, so יפה on a page is both words at once. This is not a puzzle with a trick to it — it is the ordinary condition of reading Hebrew, which beginner courses hide by printing pointed tables and then handing out unpointed text. The resolver is the noun: find what the adjective agrees with, and the reading follows from that.

The ־ִי class: the yod doubles, and the spelling shows it

A small group ends in a stressed ־ִי that is part of the word itself: נָקִי "clean", עָנִי "poor". That final yod is a consonant, and when an ending follows it, the yod doubles. In ktiv male a doubled consonantal yod is written twice, so the doubling is one of the rare stem changes you can actually see.

The first vowel reduces here too — nakí but nekiyá — so this class does the ordinary thing on top of its own trick.

Now the trap: נקי and ישראלי end in the same letter and inflect completely differently. In ישראלי the ־ִי is a suffix attached to a noun, and the feminine is ישראלית; in נקי the yod is part of the word, and the feminine is נקייה. Nothing in the spelling tells you which kind of word you are holding — that is knowledge about the word, not about the letter. The relational class has its own page, the ־ִי adjectives.

It is one rule, not three lists

The vanishing first vowel is not an adjective rule at all. It is the general behaviour of Hebrew words: an open syllable two steps in front of the stress will not hold a full vowel. Move the stress rightwards with an ending, and that vowel collapses to a shva.

The verb row is a slightly different squeeze — there the vowel lost is the one immediately before the ending — but for a learner it is one fact, not three. What Israelis then do with the resulting shva, which is to delete it and start the word with a consonant cluster, is on the shva; the noun side is on plural stem changes; and the adjectives whose stem gives way further than this — קטן, לבן, ישן — are on shifting vowels.

Common Mistakes

1. Reading יפה as one invariant word. English speakers hear yafé once and use it for everything, because in English beautiful is beautiful. Here it is two pronunciations of one spelling, and the wrong one is as audible as a wrong ending.

2. Adding the plural ending on top of the ־ֶה. You see יפה, you want a plural, you add ־ים. But the ־ֶה is the singular ending — it comes off first.

3. Giving נקי the ישראלי feminine. Two adjectives ending in the same letter, two different feminines, and the wrong one is the natural guess.

4. Keeping the citation vowel when the ending goes on. You learned גָּדוֹל as gadól, so the feminine comes out as the dictionary form with something glued to it.

Key Takeaways

• The endings are stressed, and a stressed ending squeezes out the vowel two syllables in front of it: גָּדוֹל → גְּדוֹלָה, גְּדוֹלִים, גְּדוֹלוֹת. The long o or u never moves.
• A guttural first letter takes a chataf rather than a bare shva, so it stays audible: עָצוּב → עֲצוּבָה atsuvá, חָדָשׁ → חֲדָשָׁה.
• אָרוֹךְ changes vowel quality too: arókh but aruká, arukím, arukót — and the ending hardens from kh to k. The spelling shows neither change.
• In the ־ֶה class the ending is replaced, not added: יָפֶה → יָפָה, יָפִים, יָפוֹת — and unpointed, the two singulars are one string. יפה is both yafé and yafá; only the noun resolves it.
• In the ־ִי class the yod doubles and ktiv male writes it twice: נָקִי → נקייה, נקיים, נקיות. Relational ישראלי → ישראלית is a different class that happens to rhyme.
• The vanishing vowel is one rule for the whole language — גָּדוֹל → גְּדוֹלִים beside דָּבָר → דְּבָרִים — so you learn it here and keep it for nouns and verbs.