印欧语语音定律概览

这份概览包括语言学家对印欧语系中的各种语言总结出的音变规律。每个规则都给出了简洁的描述；在各自的主页面中提供了更多详细信息。

在所有原始印欧语或多个分支内

牧牛人规则: 在 *w 或 *u 旁，圆唇软腭塞音不再圆唇。规则还指出，在原始日耳曼语中，-um- 或 -un-旁的圆唇软腭塞音不再圆唇。
格拉斯曼定律: （适用于希腊语、印度-伊朗语族）如果两个相邻音节均包含送气辅音，那么第一个送气音被异化为不送气音。规则还指出，在希腊语中，第一个送气音还会发生清化，和 *s 到 *h 的异化。
kʷetwóres规则: 若一个单词的三个音节包含é-o-X（X是任何一个元音）的元音模式，重音将会迁移到中间的音节，即形成e-ó-X。
Osthoff定律: （除去吐火罗语和印度-伊朗语族）当一个长元音后跟着一个响音和另外一个辅音，该长元音变为短元音。
Pinault定律: 喉音在辅音*y前消失。
Ruki定律: （适用于波罗的-斯拉夫，阿尔巴尼亚语，亚美尼亚语，印度-伊朗语族）*s在 *r, *u, *k 或 *i 前缩回成齿龈后音 *š。*g and *gʰ 在 *s, *r̥, *w, *y 前清化。在印度-伊朗语族中，*r 和 *l 发生融合。在斯拉夫语族中，*š 进一步收回为 *x，除非后面跟着一个前元音或 *j。
Siebs定律: 如果一个飘忽s-被加在浊辅音开头的词根上，这个浊辅音清化，并保留送气的性质。
Stang定律: 在词的末尾，当一个喉音、*y 或 *w 在一个元音之后、在一个鼻音之前，这个音（喉音、*y 或 *w）消失，其前面的元音变为长元音。
Szemerényi定律: 在词的末尾，当一个 *s 或 *h₂ 的前面依次是一个响音和一个元音，这个音（*s 或 *h₂）消失，其前面的元音变为长元音。如果结果是*-ōn，这个n也消失，最终是*-ō。

波罗的-斯拉夫

Hirt定律: If a syllable ends in a vowel (not a diphthong) followed by a laryngeal, then the accent is retracted onto that syllable if it originally fell on the following syllable. The law applies to the original PIE accent placement, but after levelling of PIE mobile-accented paradigms into end-stressed paradigms. It also applied before the epenthesis before syllabic sonorants.
Pedersen定律: In words with a (Balto-Slavic) mobile accent paradigm, the accent was retracted from a medial onto the initial syllable. In Proto-Slavic, a similar analogical change caused the retraction of the accent onto a preceding unaccented clitic, such as a preposition.
Winter定律: Short vowels (*a, *e, *i, *o, *u) are lengthened before unaspirated voiced stops (*b, *d, *g, but not *ǵ). The newly lengthened vowel receives the "acute register". The law may only have applied to vowels that were followed by a stop in the same syllable.

波罗的语族

De Saussure定律: （立陶宛语）If a non-acuted accented syllable is followed by an acuted syllable, the accent shifts forwards onto the acuted syllable. This split the Balto-Slavic fixed accent paradigm into Lithuanian paradigms 1 and 2, and the mobile accent paradigm into paradigms 3 and 4.
Hjelmslev定律: （暂缺）
Leskien定律: （立陶宛语）If a word-final long vowel or diphthong is acuted, it is shortened.^{[需要解释]}

斯拉夫语族

Dybo定律: If a syllable was non-acute and accented, the accent was advanced onto the following syllable. The originally accented syllable retains its length. The change was prevented if the word had a mobile accent paradigm.
Havlík定律: Yers (the vowels *ь and *ъ) became "strong" or "weak" in an alternating pattern, depending on their position in a word. A yer was weak unless the next syllable contained a weak yer, then it became strong. Weak yers were eventually lost, while strong yers were lowered and became other vowels.
Ivšić定律: Accented weak yers (according to Havlík's law) lost their accent to the preceding syllable, which received a "neoacute" accent.
Meillet定律: In words with a mobile accent paradigm, if the first syllable is accented with a rising (acute) accent, it is converted into a falling (circumflex) accent.
Stang定律: If a word-final syllable was long falling (circumflex) accented, the accent was retracted onto the preceding syllable. The originally accented syllable is shortened, and the newly-accented syllable receives a "neoacute" accent. This change applied after Dybo's law, and often "undid" it by shifting the accent back again.
Van Wijk定律: Short vowels, except for yers (*ь, *ъ) and nasal vowels, are lengthened when preceded by a palatal consonant.

凯尔特语族

Bergin定律: （古爱尔兰语）动词可以以连接形式放在句尾。

日耳曼语族

Cowgill定律: （未被完全接受）格林定律生效之后，喉音 *h₃（可能也包括 *h₂）若在响音之后、*w 之前，则其变为 *k。
日耳曼擦音定律: 如果一个爆破音之后是一个清音（一般是 *s 或 *t），其变为清擦音，并去圆唇化。齿音若在 *s 之前则变成 *ss，若在 *t 之前则变成 *ss（在较老的形式中）或 *st（在较老的或衍生形式中）。
格林定律: 印欧语的三组爆破音发生如下拉链式变化：清音变为擦音(*p, *t, *k, *kʷ > *f, *þ, *h, *hʷ)，浊音清化(*b, *d, *g, *gʷ > *p, *t, *k, *kʷ)，送气浊音不送气化(*bʰ, *dʰ, *gʰ, *gʷʰ > *b, *d, *g, *gʷ)。如果有两个浊阻碍音，则只有第一个变为擦音，第二个仍是爆破音。
Holtzmann定律: （北部、东部日耳曼语）重叠的半元音 *jj 和 *ww 变为重叠的爆破音。*jj 在北日耳曼语变为 *ggj，在东日耳曼语变为 *ddj，*ww 都变为 *ggw。
北海日耳曼语鼻音消失法则: （北海日耳曼语）当/n/后面跟着一个擦音时，/n/消失，前面的元音加长、鼻音化。
Kluge定律: （未被广泛接受）爆破音与之后的 *n 融合成重叠清爆破音。
Sievers定律: 后缀 *j alternates with *ij depending on the syllable weight (length) of the preceding morpheme. *j appears after "light" or "short" morphemes, which consist of a single syllable ending in a short vowel and a single consonant. *ij appears elsewhere, including all morphemes with more than one syllable.
维尔纳定律: 格林定律生效之后，非重读音节的末尾的清擦音发生浊化(*f, *þ, *h, *hʷ, *s > *b, *d, *g, *gʷ, *z)。此后，所有重音移动到第一个音节上。

印度-伊朗语族

Bartholomae定律: If cluster of two or more obstruents contains at least one voiced aspirated consonant, the whole cluster becomes voiced and aspirated.
Brugmann定律: When it is an ablaut alternant of *e, the vowel *o is lengthened and (after merging) becomes *ā when it stands at the end of a syllable.

In all words or word-groups of four or more syllables bearing the chief accent on a long syllable, a short unaccented medial vowel was necessarily syncopated, but might be restored by analogy

意大利语族

Exon定律: 在具有四个或更多音节的单词中，若第二、第三个音节是短音节，则第二个音节的元音被省略。
Lachmann定律: 若一个短元音后跟着一个底层上的浊塞音、一个清塞音，其变为长元音。