https://www.khanacademy.org/ela/9th-and-10th-grade-grammar/xf006c25352e869bb:nouns-9/xf006c25352e869bb:plural-nouns-9/a/regular-and-irregular-plural-nouns-grammar-9 2026-07-14T15:00:54.021605571Z Regular and irregular plural nouns Learn how to form the plurals of regular and irregular nouns. article https://www.khanacademy.org/humanities/grammar/parts-of-speech-the-noun/irregular-plural-nouns-base-plurals-and-irregular-endings/v/irregular-plural-nouns-part-i-the-parts-of-speech-grammar-khan-academy 2026-07-19T06:05:50.693875657Z Irregular plural nouns: -f to -ves plurals Not all English nouns can be made plural only by adding an "s" to the end. These are called irregular plurals. Many words that end in "f", like "leaf", "loaf", and "calf", change their sound when they become plural: "leaves", "loaves", and "calves". video https://cdn.kastatic.org/googleusercontent/3a05CIUtVGdhAMRT3vYvk41jc0tF0XLmrl4Dt9Hsc-sHr1wQcJrl41TBsq8-XacH5bL6AIJRMlGwJuT_9QK1RXLv Irregular plural nouns: -f to -ves plurals Not all English nouns can be made plural only by adding an "s" to the end. These are called irregular plurals. Many words that end in "f", like "leaf", "loaf", and "calf", change their sound when they become plural: "leaves", "loaves", and "calves". https://cdn.kastatic.org/ka-youtube-converted/hhBhHW__Oxg.mp4/hhBhHW__Oxg.mp4 187 Plural nouns https://www.khanacademy.org/humanities/grammar/parts-of-speech-the-noun/irregular-plural-nouns-base-plurals-and-irregular-endings/v/irregular-plural-nouns-part-ii-the-parts-of-speech-grammar-khan-academy 2023-09-19T21:32:47.781412264Z Irregular plural nouns: -en plurals We talk about irregular plurals in English, focusing on the "en" ending. David explains that "child" becomes "children" and "ox" becomes "oxen. video https://cdn.kastatic.org/googleusercontent/KZ1yeFSI0ZBzH36EwhEL-rXGeK5Pq0KUBWRNEPVMw-SLna6R_oXWv76zg29KBV-7xeB8BMCR84DImaaB-MwS6Eqh5A Irregular plural nouns: -en plurals We talk about irregular plurals in English, focusing on the "en" ending. David explains that "child" becomes "children" and "ox" becomes "oxen. https://cdn.kastatic.org/ka-youtube-converted/n9poHOKkF28.mp4/n9poHOKkF28.mp4 443 Plural nouns https://www.khanacademy.org/ela/9th-and-10th-grade-grammar/xf006c25352e869bb:nouns-9/xf006c25352e869bb:plural-nouns-9/e/irregular-plurals-that-end-in-ves-and-en 2026-07-13T19:41:05.916442654Z Irregular plurals that end in -ves and -en Practice recognizing and forming irregular plurals Amanda Leff exercise https://www.khanacademy.org/humanities/grammar/parts-of-speech-the-noun/irregular-plural-nouns-base-plurals-and-irregular-endings/v/irregular-plurals-the-base-plural 2021-09-02T15:20:35.158460229Z Irregular plural nouns: the base plural Some nouns look the same whether they're singular or plural – these nouns are called "base plurals", and we'll demonstrate how they behave the only way I know how... by using sheep! video https://cdn.kastatic.org/googleusercontent/DaLed8iEF6ZgNOqo048ORZtO80087JsScwjMBwiwXOOW4YB4G3-p-YEL68qMVtFgWBvuxxuJbze5AE-yi6pZV54OUw Irregular plural nouns: the base plural Some nouns look the same whether they're singular or plural – these nouns are called "base plurals", and we'll demonstrate how they behave the only way I know how... by using sheep! https://cdn.kastatic.org/ka-youtube-converted/UnJmPywSSvg.mp4/UnJmPywSSvg.mp4 307 Plural nouns https://www.khanacademy.org/humanities/grammar/parts-of-speech-the-noun/irregular-plural-nouns-mutant-and-foreign-plurals/v/irregular-plural-nouns-part-iv-the-parts-of-speech-grammar 2022-11-16T04:22:43.7414897Z Irregular plural nouns: mutant plurals English has seven MUTANT PLURALS—irregular nouns that change their vowel sounds when they go from singular to plural. Because of weird language reasons, they don't form plurals normally. Those nouns are "foot", "woman", "man", "tooth", "goose", "mouse", and "louse". They become "feet", "women", "men", "teeth", "mice", and "lice". video https://cdn.kastatic.org/googleusercontent/MWUhGzw4hDxExVeoZLBnc5KeyA1_hMiVfasqZhX52DYGamZVDx-ab10Vvk6WaRIjwHGcTD3Mjavv74lrmiMmcT3F Irregular plural nouns: mutant plurals English has seven MUTANT PLURALS—irregular nouns that change their vowel sounds when they go from singular to plural. Because of weird language reasons, they don't form plurals normally. Those nouns are "foot", "woman", "man", "tooth", "goose", "mouse", and "louse". They become "feet", "women", "men", "teeth", "mice", and "lice". https://cdn.kastatic.org/ka-youtube-converted/VdLOP9teko4.mp4/VdLOP9teko4.mp4 162 Plural nouns https://www.khanacademy.org/humanities/grammar/parts-of-speech-the-noun/irregular-plural-nouns-mutant-and-foreign-plurals/v/foreign-plurals-grammar 2021-09-02T15:20:35.158460229Z Irregular plural nouns: foreign plurals You don't need to know how to speak Latin and Greek in order to understand English, but some words in English come from those languages. It's helpful to know how some Greek and Latin words change from singular to plural. video https://cdn.kastatic.org/googleusercontent/QMiA10nF8pUunvl_-EXo_HuxrbJho_oWfQp2B5aIHYqH2tEga3jSlTDCHtNmhI2p3elUagASbd6y9vVTJSClNPA0 Irregular plural nouns: foreign plurals You don't need to know how to speak Latin and Greek in order to understand English, but some words in English come from those languages. It's helpful to know how some Greek and Latin words change from singular to plural. https://cdn.kastatic.org/ka-youtube-converted/L6pH8O3B4ak.mp4/L6pH8O3B4ak.mp4 297 Plural nouns https://www.khanacademy.org/ela/9th-and-10th-grade-grammar/xf006c25352e869bb:nouns-9/xf006c25352e869bb:plural-nouns-9/e/base-mutant-and-foreign-plurals-grammar-9 2026-07-13T19:41:05.916442654Z Base, mutant, and foreign plurals Practice recognizing and forming base, mutant, and foreign plurals. Amanda Leff exercise