| ItalitalItalian man, Italian personNoun | Noun |
| ItálieitálieItalyNoun | Noun |
| ItalkaitalkaItalian woman, Italian personNoun | Noun |
| italskyin ItalianAdverb | Adverb |
| italštinaItalianNoun | Noun |
| jáIPronoun | Pronoun |
| Já jsemjá jsemI amPhrase | Phrase |
| já nerad/aI'd rather notPhrase | Phrase |
| jablkoappleNoun | Noun |
| jahodastrawberryNoun | Noun |
| jahodovýstrawberryAdjective | Adjective |
| jachtayachtNoun | Noun |
| jakhowAdverb | Adverb |
| jak častohow oftenWord combination | Word combination |
| jak dalekohow farWord combination | Word combination |
| jak dlouhohow longWord combination | Word combination |
| jak rychlehow quicklyWord combination | Word combination |
| jak se čtehow is it readPhrase | Phrase |
| jak se jmenujewhat is it calledPhrase | Phrase |
| jak se píšehow is it written?Phrase | Phrase |
| jak se řekne českyhow do you say it in Czech?Phrase | Phrase |
| jak se správně vyslovuje slovohow is the word pronounced correctly?Phrase | Phrase |
| jak se ti/vám líbíhow do you like it?Phrase | Phrase |
| jak se vyslovujehow is it pronounced?Phrase | Phrase |
| jak starýhow oldWord combination | Word combination |
| jak ti/vám chutnáhow do you like the taste?Phrase | Phrase |
| jak vysokohow highWord combination | Word combination |
| jak vysokýhow tall; how highWord combination | Word combination |
| jakoas, likeConjunction | Conjunction |
| jakýwhat kind, howPronoun | Pronoun |
| jaký význam má slovowhat does the word mean?Phrase | Phrase |
| jakžtakžso-soAdverb | Adverb |
| JaponecjaponecJapanese man, Japanese personNoun | Noun |
| JaponkajaponkaJapanese woman, Japanese personNoun | Noun |
| JaponskojaponskoJapanNoun | Noun |
| japonskyin JapaneseAdverb | Adverb |
| japonštinaJapaneseNoun | Noun |
| jarníspringAdjective | Adjective |
| jarospringNoun | Noun |
| jasněclearly, sureAdverb | Adverb |
| jasnoclearAdverb | Adverb |
| jasnýclear; obviousAdjective | Adjective |
| játraliverNoun | Noun |
| jazyk (část těla)tongueNoun | Noun |
| jazyk (řeč)languageNoun | Noun |
| jazykovýlanguageAdjective | Adjective |
| jazykylanguagesNoun | Noun |
| jazzjazzNoun | Noun |
| jazzklubjazz clubNoun | Noun |
| jazzovýjazzAdjective | Adjective |
| jde toit is going okay; it is manageablePhrase | Phrase |
| jégeeInterjection | Interjection |
| je chyba, žeit is a mistake thatPhrase | Phrase |
| je jasné, co říkámis it clear what I am saying?Phrase | Phrase |
| je mi to lítoI am sorry about itPhrase | Phrase |
| je mi x letI am X years oldWord combination | Word combination |
| je možné, žeit is possible thatGrammar pattern | Grammar pattern |
| je od tebe/vás hezkéthat is nice of youPhrase | Phrase |
| je od tebe/vás miléthat is kind of youPhrase | Phrase |
| je od vás hezké, žeit is nice of you thatPhrase | Phrase |
| je (po)třebait is necessary; it is neededWord combination | Word combination |
| je škoda, žeit is a pity thatPhrase | Phrase |
| je to dobřeit is good; it is okayPhrase | Phrase |
| je to fajnit is finePhrase | Phrase |
| je to jednoit does not matterPhrase | Phrase |
| je to miléthat is kindPhrase | Phrase |
| je to možnéit is possiblePhrase | Phrase |
| je to nudnéit is boringPhrase | Phrase |
| je to O.K.je to o.k.it is OKPhrase | Phrase |
| je to pravdais it true?; it is truePhrase | Phrase |
| je to takthat is right; that is soPhrase | Phrase |
| je to v pořádkuit is all right; it is okayPhrase | Phrase |
| je třebait is necessary; it is neededWord combination | Word combination |
| je zakázánoit is forbiddenWord combination | Word combination |
| je zavřenoit is closedWord combination | Word combination |
| jedenoneNumber | Number |
| jedenáctelevenNumber | Number |
| jedinýonly; singleAdjective | Adjective |
| jednánínegotiationsNoun | Noun |
| jednatelmanaging directorNoun | Noun |
| jednatelkafemale managing directorNoun | Noun |
| jedničkanumber one, grade ANoun | Noun |
| jednoduchýsimpleAdjective | Adjective |
| jednohubkacanape, small biteNoun | Noun |
| jednolůžkovýsingle-roomAdjective | Adjective |
| jednotlivěindividuallyAdverb | Adverb |
| jednouonceNumber | Number |
| jedovatýpoisonousAdjective | Adjective |
| jehohisPronoun | Pronoun |
| jelendeer, stagNoun | Noun |
| jemnýdelicate; fine; gentleAdjective | Adjective |
| jenonlyAdverb | Adverb |
| jenomonlyAdverb | Adverb |
| jeslenursery, crecheNoun | Noun |
| jestliif, whetherConjunction | Conjunction |
| ještěeven, still, again, yet, moreAdverb | Adverb |
| ještě jednouonce more; one more timePhrase | Phrase |
| Ještě jednou, prosímještě jednou, prosímone more time, pleasePhrase | Phrase |
| ještě nikdynever before; not ever yetPhrase | Phrase |
| jetgo by vehicle; rideVerb | Verb |