| každýeach, everyPronoun | Pronoun |
| kdewhereAdverb | Adverb |
| kdowhoPronoun | Pronoun |
| kdo volá, prosímwho is calling, pleasePhrase | Phrase |
| kdokolianyonePronoun | Pronoun |
| kdywhenAdverb | Adverb |
| kdybyifConjunction | Conjunction |
| kdysionce (in the past)Adverb | Adverb |
| kdyžwhenConjunction | Conjunction |
| když myslíteif you say so; if you think soPhrase | Phrase |
| když to říkáteif you say soPhrase | Phrase |
| kečupketchupNoun | Noun |
| kelímekcup; small containerNoun | Noun |
| kempcampsite; campNoun | Noun |
| keřbush; shrubNoun | Noun |
| kilokilogram; kiloNoun | Noun |
| kilogramkilogram; kiloNoun | Noun |
| kilometrkilometerNoun | Noun |
| kilometr čtverečnísquare kilometreWord combination | Word combination |
| kinocinema; movie theaterNoun | Noun |
| klasickýclassic; classicalAdjective | Adjective |
| kláštermonasteryNoun | Noun |
| klávesnicekeyboardNoun | Noun |
| klavírpianoNoun | Noun |
| klavíristapianistNoun | Noun |
| klavírnípianoAdjective | Adjective |
| klenotgem; jewelNoun | Noun |
| klenotnictvíjewelry storeNoun | Noun |
| klepatknock; tapVerb | Verb |
| klesatfall; decreaseVerb | Verb |
| klesnoutdrop; fallVerb | Verb |
| klíčkeyNoun | Noun |
| klidpeace; quietNoun | Noun |
| klidněfeel free, no problemParticle | Particle |
| klidnýcalm; quietAdjective | Adjective |
| klientclientNoun | Noun |
| klikatclickVerb | Verb |
| klikatýwinding; zigzagAdjective | Adjective |
| kliknoutclick onceVerb | Verb |
| kloboukhatNoun | Noun |
| klouzatslide; be slipperyVerb | Verb |
| klubclubNoun | Noun |
| klukboyNoun | Noun |
| knedlíkdumplingNoun | Noun |
| knihabookNoun | Noun |
| knihkupectvíbookstoreNoun | Noun |
| knihovnalibrary; bookcaseNoun | Noun |
| knírmustacheNoun | Noun |
| knížkalittle book; bookNoun | Noun |
| kobereccarpet; rugNoun | Noun |
| kočičkakitty; little catNoun | Noun |
| kočkacatNoun | Noun |
| kodiakKodiak bearNoun | Noun |
| kofolaKofola; Czech soft drinkNoun | Noun |
| kohoutrooster; cockNoun | Noun |
| kojitbreastfeedVerb | Verb |
| kolacolaNoun | Noun |
| koláčcake; pastryNoun | Noun |
| koledacarolNoun | Noun |
| kolegacolleagueNoun | Noun |
| kolegyněfemale colleagueNoun | Noun |
| kolej (doprava)rail trackNoun | Noun |
| kolej (ubytování)dormitory; student residenceNoun | Noun |
| kolekrevenue stampNoun | Noun |
| kolektivteam; groupNoun | Noun |
| kolemaroundPreposition | Preposition |
| kolenokneeNoun | Noun |
| kolibříkhummingbirdNoun | Noun |
| kolikhow many, how muchNumber | Number |
| kolikátýwhich, what number in orderNumber | Number |
| kolikráthow many timesNumber | Number |
| kolobike; bicycle; wheelNoun | Noun |
| kolo (jízdní kolo)bicycle; bikeNoun | Noun |
| kolo (kolo u auta)wheelNoun | Noun |
| komediecomedyNoun | Noun |
| KomenskýkomenskýComeniusNoun | Noun |
| komentovanýcommented; with commentaryAdjective | Adjective |
| komentovatcommentVerb | Verb |
| komerčnícommercialAdjective | Adjective |
| komisařcommissioner; officerNoun | Noun |
| komodachest of drawersNoun | Noun |
| komorachamber; storage roomNoun | Noun |
| komplikacecomplicationNoun | Noun |
| komplikovanýcomplicatedAdjective | Adjective |
| komunikacecommunicationNoun | Noun |
| komunikativnícommunicativeAdjective | Adjective |
| komunikovatcommunicateVerb | Verb |
| komunismuscommunismNoun | Noun |
| komunistacommunistNoun | Noun |
| komunistickýcommunistAdjective | Adjective |
| konat setake place; be heldVerb | Verb |
| koncentračníconcentrationAdjective | Adjective |
| koncertconcertNoun | Noun |
| koncertníconcertAdjective | Adjective |
| koncertní sálconcert hallWord combination | Word combination |
| končitend; finishVerb | Verb |
| konecendNoun | Noun |
| konečněfinallyAdverb | Adverb |
| konečnýfinalAdjective | Adjective |
| konferenceconferenceNoun | Noun |