I-Yod / I-Waw verbs פ״י · פ״ו pe-yod · pe-waw
Many verbs listed with an initial י originally began with ו. So in the Qal imperfect the first letter disappears (וַיֵּשֶׁב he dwelt), while in the Hiphil and Niphal the ו comes back (הוֹלִיד he fathered). A few verbs that were י from the start keep it as a long vowel (וַיִּיצֶר he formed, Gen 2:7). This page shows these three patterns one by one in words actually used in the Bible.
י or ו in the פ (first root) position
Colour key blue = added at the front · orange = added at the end · purple = a mark inside (dot · doubled letter · changed vowel) · underline = the word this page is about
1What I-Yod verbs are
Many verbs are listed in the lexicon with י (yod) as the first letter — יָשַׁב (sit, dwell) · יָרַד (go down) · יָדַע (know) · יָלַד (bear) · יָצָא (go out) · יָצַר (form) · יָרֵא (fear) · יָטַב (be good).
They are weak because the first י disappears in some forms, shows up as ו (waw) in others, and in still others merges with a vowel into a long vowel.
They fall into two groups. (1) Most were originally I-Waw: in Hebrew a word-initial ו became י, so the lexical form has י, but the old ו reappears in the Hiphil and Niphal (הוֹלִיד he fathered). (2) A few are original I-Yod (יָטַב be good · יָנַק suck); in these the י stays as a vowel letter (יִיטַב).
2Where the name comes from — פ״י Pe-Yod · פ״ו Pe-Waw
Traditional grammar names the root positions after the model verb פָּעַל (pa‘al, “do”): first = פ (pe), second = ע (‘ayin), third = ל (lamed).
So a verb with י in the first position is Pe-Yod (פ״י), and one that originally had ו there is Pe-Waw (פ״ו). English grammars also write I-Yod and I-Waw. The two groups part ways in the Qal imperfect, so this page treats them together.
3At a glance — four signs
- Qal imperfect · wayyiqtol (original ו)The first י is not seen and the prefix vowel is ֵ (e) — וַיֵּשֶׁב (and he dwelt, Gen 4:16).
- Qal imperfect · wayyiqtol (original י, and a few like ירא)The prefix vowel ִ and the י merge into a long ִי (i) — וַיִּיצֶר (and he formed, Gen 2:7).
- Imperative · infinitive constructThe first י drops; the infinitive adds ת at the end — שֵׁב (sit, Gen 20:15) · לָשֶׁבֶת (to dwell, Gen 13:6).
- Hiphil · Niphal (original ו)The old ו appears as וֹ (o) — הוֹלִיד (he fathered, Gen 11:27) · הַנּוֹלַד (born, Gen 21:3).
4Paradigm — ישׁב (sit, dwell; originally ו) and יטב (be good; originally י)
Blue is what stands in front; purple is where the first root letter י / ו has changed. For יטב only well-established forms are given.
| Form | ישׁב | Reading | יטב | Reading |
|---|---|---|---|---|
| Qal perfect (he) | יָשַׁב | yashav | יָטַב | yatav |
| Qal imperfect (he) | יֵשֵׁב | yeshev | יִיטַב | yitav |
| wayyiqtol (and he) | וַיֵּשֶׁב | vayyeshev | וַיִּיטַב | vayyitav |
| imperative (2ms) | שֵׁב | shev | — | — |
| infinitive construct | שֶׁבֶת | shevet | — | — |
| participle (ms) | יֹשֵׁב | yoshev | — | — |
| Niphal perfect (he) | נוֹשַׁב | noshav | — | — |
| Niphal imperfect (he) | יִוָּשֵׁב | yivvashev | — | — |
| Hiphil perfect (he) | הוֹשִׁיב | hoshiv | הֵיטִיב | hetiv |
| Hiphil imperfect (he) | יוֹשִׁיב | yoshiv | יֵיטִיב | yetiv |
| Hophal perfect (he) | הוּשַׁב | hushav | — | — |
In the perfect and participle a vowel follows the first י, so it shows as in a strong verb. The changes come where something is prefixed (imperfect, Hiphil, Niphal) and in the imperative and infinitive.
5Why the forms change — the sound reasons
- 1. A word-initial ו became יHebrew turned a word-initial w-sound into y. So a root that was ו-שׁ-ב is listed as יָשַׁב. When something is prefixed and the ו is no longer first, the old ו can survive.
- 2. The Qal imperfect is built without the first letterIn original I-Waw verbs the Qal imperfect, imperative and infinitive construct are built on the last two root letters. The prefix stands in an open syllable and its vowel lengthens to “e” (ֵ) → יֵשֵׁב. The infinitive construct adds ת at the end instead → שֶׁבֶת.
- 3. “aw” becomes “o”After the Hiphil prefix הַ or the Niphal נַ the old ו gives “haw-, naw-”; this “aw” contracts to “o” → הוֹשִׁיב (hoshiv) · נוֹלַד (nolad). In the Niphal imperfect the ו is a consonant, doubled with a dot → יִוָּלֵד.
- 4. “iy, ay” become “i, e”In original I-Yod verbs the prefix vowel merges with י: “iy” becomes long “i” (יִיטַב), and the Hiphil “hay-” becomes “he-” (הֵיטִיב). The י stays in writing as a vowel letter.
6Qal imperfect · wayyiqtol (original ו) — real examples from the Bible
The prefix vowel is ֵ (e) and only two root letters are visible. Restore the missing first י to find the root.
vayyered — and he came down
וַיֵּ + רֶד. Root י-ר-ד (go down): “YHWH came down to see the city and the tower.”
YLVAnd YHWH came down to see the city and the tower which the sons of man (adam) had built.
vayyeda‘ — and he knew
וַיֵּ + דַע. Root י-ד-ע (know). The final ע is a guttural, so the last vowel is ַ (a).
YLVAnd Cain knew his woman (ishah), and she conceived and bore Enoch; and he was building a city, and he called the name of the city after the name of his son, Enoch.
vatteled — and she bore
וַתֵּ (and she — ת, vowel ֵ) + לֶד. Root י-ל-ד (bear): Eve bore Cain. The person prefix changes (ת), but its vowel ֵ stays.
YLVAnd Adam knew Eve his wife; and she conceived and bore Cain, and said: "I have gotten a man (ish), YHWH."
7Verbs that keep ִי (i) — original I-Yod verbs and יצר ישׁן ירא
In these verbs the first י does not vanish in the imperfect; it merges with the prefix vowel ִ into a long “i.” The dot in the prefix comes from the wayyiqtol וַ.
vayyitser — and he formed
וַיִּ (and he) + י (the first root letter, kept as a vowel letter) + צֶר. Root י-צ-ר (form). Two יs appear: the first is “he,” the second the root letter. In the perfect יָצָר (2:8) the root י stands plainly at the front.
YLVAnd YHWH God formed Adam of dust (aphar) from the ground (adamah), and breathed into his nostrils the breath (neshamah) of life, and Adam became a living soul (nephesh).
vayyitser — and he formed
The same word as וַיִּיצֶר in 2:7, with the same sound, but the second י is not written (a defective spelling). The ִ alone stands for long “i.” With only two root letters visible, restore the י to find י-צ-ר.
YLVAnd YHWH God formed out of the ground (adamah) every living thing (chai) of the field and every bird of the heavens, and brought it to Adam to see what he would call it; and whatever Adam called it, the living soul (nephesh), that was its name.
vayyishan — and he slept
וַיִּ (and he) + י (first root letter) + שָׁן. Root י-שׁ-ן (sleep). Verbs of state like “fall asleep” keep the ִי.
YLVAnd YHWH God caused a deep sleep to fall upon Adam, and he slept, and he took one of his ribs and closed up flesh (basar) in its place.
hetiv — (he) treated well
Hiphil perfect: הֵ (Hiphil prefix) + י (the first root letter — “hay-” merged into “he-”) + טִיב. An original I-Waw verb would have הוֹ (ho) here (הוֹלִיד); that is how we know יטב is originally I-Yod.
YLVAnd he dealt well with Abram for her sake; and he had sheep, and oxen, and male donkeys, and male servants, and female servants, and female donkeys, and camels.
8Imperative · infinitive construct — the first י drops
shev — dwell
Imperative (2ms). From י-שׁ-ב the first י dropped, leaving שׁ ב. Abimelech tells Abraham, “dwell where it is good in your eyes.”
YLVAnd Abimelech said, "Behold, my land is before you; dwell where it is good in your eyes."
redu — go down (you all)
Imperative (2mp): רְד + וּ (you all). Root י-ר-ד. Jacob tells his sons to “go down” to Egypt.
YLVAnd he said, "Behold, I have heard that there is grain in Egypt; go down there and buy for us from there, that we may live and not die."
da‘ — know
Imperative: the first י of י-ד-ע dropped, leaving two letters; the guttural ע gives ַ.
YLVAnd now, restore the man's (ish) wife (ishah); for he is a prophet, and he shall pray for you, and you shall live; but if you do not restore her, know that you shall surely die, you and all that are yours."
lashevet — to dwell
לָ (to) + שֶׁבֶ + ת. The infinitive construct drops the first י and adds ת at the end. “The land could not support them dwelling together.”
YLVAnd the land did not bear them to dwell together, for their possessions were great, and they were not able to dwell together.
lada‘at — knowing
לָ + דַעַ + ת, the infinitive construct of י-ד-ע. Because of the guttural ע the vowels are “a” (דַעַת), not “e.” “… like one of us, knowing good and evil.”
YLVAnd YHWH God said, "Behold, Adam has become like one of us, to know good and evil; and now, lest he put forth his hand and take also of the tree of life (chai), and eat, and live forever—"
9Hiphil · Niphal — the original ו reappears
When a prefix keeps the ו from being first, the letter written י in the lexical form shows up as ו.
vattotse — and it (she) brought forth
Hiphil wayyiqtol: וַתּ (and she) + וֹ (the original ו) + צֵא. The Hiphil of י-צ-א (go out) → “bring forth.” The י of the lexical form is וֹ here. “The earth” is feminine, hence ת. תּוֹצֵא in 1:24 is the same form.
YLVAnd the earth brought forth vegetation, herb yielding seed after its kind, and tree making fruit, in which is its seed, after its kind; and God saw that it was good.
vayyoled — and he fathered
Hiphil wayyiqtol: וַיּ + וֹ + לֶד, the same Hiphil as הוֹלִיד (11:27), with the final vowel shortened to ֶ. It differs from the Qal wayyiqtol וַתֵּלֶד (she bore, 4:1) by the first vowel (וֹ vs ֵ).
YLVAnd Adam lived thirty and a hundred years, and he begot in his likeness, after his image, and he called his name Seth.
yivvaled — shall (a child) be born
Niphal imperfect: יִ (he) + וָּ (dotted ו) + לֵד. The Niphal imperfect dots the first root letter (יִקָּרֵא); here that first letter is the original ו, so the ו carries the dot. “Shall a child be born to a man of a hundred?”
YLVAnd Abraham fell upon his face and laughed, and said in his heart, "Shall a child be born to one who is a son of a hundred years? And shall Sarah, who is a daughter of ninety years, bear?"
10Perfect · participle — the first י stays
yotse — going out
Qal participle: יֹ (“o” on the first letter) + צֵא. Root י-צ-א: “a river going out from Eden.” The final א is silent (see “III-Aleph verbs”).
YLVAnd a river was going out from Eden to water the garden, and from there it parted and became four heads.
11Easy to confuse
וַיִּירָא (he feared) and וַיַּרְא (he saw). וַיִּירָא (Gen 28:17) is from י-ר-א (fear), a verb that keeps ִי. וַיַּרְא (1:4) is the shortened wayyiqtol of ר-א-ה (see) — see “III-He verbs.” The same verse 28:17 has נּוֹרָא (awesome), whose Niphal וֹ shows that ירא is originally I-Waw (the dot in its first letter comes from being read together with the preceding מַה).
Prefix vowel ֵ = Qal, וֹ = Hiphil. וַתֵּלֶד (she bore, 4:1) is Qal; וַיּוֹלֶד (he fathered, 5:3) is Hiphil. Both end in לֶד, so the first vowel decides.
ֹ without the ו letter. The Hiphil וֹ is sometimes written with just the dot ֹ — וַתֹּסֶף (and she again …, 4:2; root י-ס-ף add). Even without the letter ו, the “o” sound marks the Hiphil.
A few merge like I-Nun verbs. Verbs such as יצק (pour) and יצת (burn) assimilate the first י into a dot in the next letter. If only two root letters are visible and one has a dot, consider this case as well as I-Nun.