- What is the grammatical rule that causes some vowels to become Kamats at the end of a sentence in the Torah?
- What vowels usually undergo this change?
For example: גַן to גָן.
Thank you.
For example: גַן to גָן.
Thank you.
Some background:
A pausal form is a word that appears in a special form (usually) at disjunctive cantillation signs (like silluq, etnaḥta, and sometimes some others). For example, we have the contextual form (the opposite of a pausal form) שָׁמְרוּ (with accent on the last syllable, eg. Gen 18:19) versus the pausal form שָׁמָרוּ (with accent on the penultimate syllable, eg. Gen 41:35).
From a historical linguistics point of view, the pausal forms generally preserve an older structure of the word than the contextual form. In the example of שמרו, we know (from comparison to other Semitic languages, as well as internal-to-Hebrew arguments) that the older form is *shamárū (the * represents reconstructed forms), with short a vowels. The word underwent pretonic lengthening, in which the vowel before the stress was lengthened, so we have *shāmárū. In pause, we get pausal lengthening (which is a lengthening of the stress vowel for rhetorical purposes/better pronunciation/etc.), so we have the pausal form shāmā́rū. However, in context, the second vowel remained short, and the accent eventually shifted to the last syllable, *shāmarū́, and then the short (now-)unaccented middle vowel was reduced to a shewa, so we get shāmərū́ (this stress shift mainly occurred with either two successive closed syllables, or two successive open syllables with a short penultimate vowel, hence shāmā́rū was unaffected).
Back to your question:
To understand which words exhibit a qamats ā in pause but not in context, we have to understand what has happened to older a vowels throughout the history of (proto-)Hebrew. Here are some of the main cases:
However, not all segolates derive from an older a vowel. For example, צֶדֶק derives from *ṣidq, and so in pause we don't get a qamats (eg. Psa 119:172). Internal evidence to the i vowel is often found by looking at the construct form, and here we have ṣidqō צִדְקוֹ (eg. Isa 42:21). Other words that you might think have an a vowel reflect other vowel shifts, and historically derive from an i vowel. For example, מֶלֶךְ remains a segolate in pause (eg. Gen 14:17), even though the construct from has an a vowel in malkō מַלְכּוֹ (eg. Num 24:7). However, מֶלְךְ actually derives from *milk, and the a vowel is due to Phillipi's Law — see more details about this vowel shift versus pausal lengthening here.
All said, the vowel signs you expect to "become" qamats in pause are pataḥ, shewa, and segol (I put "become" in quotation marks, because as we see above, the a vowel in pause is really more original than a shewa or segol, and it's only in the pataḥ case that we see pure pausal lengthening). For segolate nouns, you really have to know the original vowel of the word to hope to predict what will happen in pause.
Extensive details can be found in Dr. Joshua Blau's Phonology and Morphology of Biblical Hebrew, whence most of this information. This answer glosses over the difference between the quantitative difference between short and long a vowels and the qualitative difference between pataḥ and qamats.
ללבון מגזרת לבנה. ובנין הלבנים חזק מהאבנים כי בנין העפר יזיקהו המים ובנין האבנים יזיקהו האש וכן כתוב ותהי להם הלבנה לאבן והחמר היה להם לחמר. ודע כי יש שמות לא ישתנו ממעלתם באתנח או בסוף פסוק בבעלי קמץ קטן. כמו ספר. ובבעלי פתח קטן כמו צדק. והנה כן תבן וטעמה לא נודע רק ככה נמצאו: TO MAKE BRICK. Lilbon (to make brick) comes from the same root as levenah (brick). A brick structure is stronger than a stone structure, because a structure made out of soil will be damaged by water and a stone structure will be harmed by fire. It is similarly written, And they had brick for stone, and slime had they for mortar (Gen. 11:3). Note, there are nouns that are vocalized with a tzere, such as the word sefer (book), or a segol, i.e., tzedek (righteousness), whose status does not change at an etnach or at the end of a verse. The word teven (straw) falls into this category. We not know the reason for the this; however, such is the case.