Common Czech is a colloquial variant of the Czech language

Czech language

Czech is a West Slavic language with about 12 million native speakers; it is the majority language in the Czech Republic and spoken by Czechs worldwide. The language was known as Bohemian in English until the late 19th century...

. It is usually defined as an interdialect used in common speech in Bohemia

Bohemia

Bohemia is a historical region in central Europe, occupying the western two-thirds of the traditional Czech Lands. It is located in the contemporary Czech Republic with its capital in Prague...

 and western parts of Moravia

Moravia

Moravia is a historical region in Central Europe in the east of the Czech Republic, and one of the former Czech lands, together with Bohemia and Silesia. It takes its name from the Morava River which rises in the northwest of the region...

 (about 2/3 of all inhabitants of the Czech Republic

Czech Republic

The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....

). Common Czech is not codified

Codification (linguistics)

In linguistics, codification is the process of standardizing and developing a norm for a language.Codifying a language can vary from case to case and depends on the stage of standardization that already exists...

, but some of its elements can get into the standard language. Since the second half of the 20th century, Common Czech elements have also been spreading to regions previously unaffected, as a consequence of the media's influence.

Morphology and phonology

Common Czech is characterized by quite regular differences from the standard morphology

Morphology (linguistics)

In linguistics, morphology is the identification, analysis and description, in a language, of the structure of morphemes and other linguistic units, such as words, affixes, parts of speech, intonation/stress, or implied context...

 and phonology

Phonology

Phonology is, broadly speaking, the subdiscipline of linguistics concerned with the sounds of language. That is, it is the systematic use of sound to encode meaning in any spoken human language, or the field of linguistics studying this use...

. These variations are more or less common to all Common Czech dialect

Dialect

The term dialect is used in two distinct ways, even by linguists. One usage refers to a variety of a language that is a characteristic of a particular group of the language's speakers. The term is applied most often to regional speech patterns, but a dialect may also be defined by other factors,...

s:

• é usually replaced by ý/í: malý město (small town), plamínek (little flame), lítat (to fly);
• ý (sometimes also í) replaced by ej: malej dům (small house), mlejn (mill), plejtvat (to waste), bejt (to be) – as a consequence of the loss of the difference in the pronunciation of y/ý and i/í in the 15th century;
• unified plural
  Plural
  In linguistics, plurality or [a] plural is a concept of quantity representing a value of more-than-one. Typically applied to nouns, a plural word or marker is used to distinguish a value other than the default quantity of a noun, which is typically one...
  
   endings of adjective
  Adjective
  In grammar, an adjective is a 'describing' word; the main syntactic role of which is to qualify a noun or noun phrase, giving more information about the object signified....
  
  s: malý lidi (small people), malý ženy (small women), malý města (small towns) – stand.: malí lidé, malé ženy, malá města;
• unified instrumental
  Instrumental case
  The instrumental case is a grammatical case used to indicate that a noun is the instrument or means by or with which the subject achieves or accomplishes an action...
  
   ending -ma in plural
  Plural
  In linguistics, plurality or [a] plural is a concept of quantity representing a value of more-than-one. Typically applied to nouns, a plural word or marker is used to distinguish a value other than the default quantity of a noun, which is typically one...
  
  : s těma dobrejma lidma, ženama, chlapama, městama (with the good people, women, guys, towns) – stand.: s těmi dobrými lidmi, ženami, chlapy, městy (in essence, this form resembles the form of the dual
  Dual (grammatical number)
  Dual is a grammatical number that some languages use in addition to singular and plural. When a noun or pronoun appears in dual form, it is interpreted as referring to precisely two of the entities identified by the noun or pronoun...
  
  , which was once a productive form, but now is almost extinct, except a few examples; in Common Czech it can often be used indiscriminately, i.e. it can substitute a regular plural form, not just as it was once used);
• prothetic v- added to most words beginning o-: votevřít vokno (to open the window) – stand.: otevřít okno; but ovoce not *vovoce (fruit)
• omitting of the syllabic -l in masculine ending of the past participle
  Participle
  In linguistics, a participle is a word that shares some characteristics of both verbs and adjectives. It can be used in compound verb tenses or voices , or as a modifier...
  
  s: řek (he said), moh (he could), pích (he pricked) – stand.: řekl, mohl, píchl.

Example of declension

(with the comparison with the standard Czech)

		Masculine animate	Masculine inanimate	Feminine	Neuter
Sg.	Nominative	mladej člověk mladý člověk	mladej stát mladý stát	mladá žena mladá žena	mladý zvíře mladé zvíře
	Genitive	mladýho člověka mladého člověka	mladýho státu mladého státu	mladý ženy mladé ženy	mladýho zvířete mladého zvířete
	Dative	mladýmu člověkovi mladému člověku	mladýmu státu mladému státu	mladý ženě mladé ženě	mladýmu zvířeti mladému zvířeti
	Accusative	mladýho člověka mladého člověka	mladej stát mladý stát	mladou ženu mladou ženu	mladý zvíře mladé zvíře
	Vocative	mladej člověče! mladý člověče!	mladej státe! mladý státe!	mladá ženo! mladá ženo!	mladý zvíře! mladé zvíře!
	Locative	mladym člověkovi mladém člověkovi	mladym státě mladém státě	mladý ženě mladé ženě	mladym zvířeti mladém zvířeti
	Instrumental	mladym člověkem mladým člověkem	mladym státem mladým státem	mladou ženou mladou ženou	mladym zvířetem mladým zvířetem
Pl.	Nominative	mladý lidi mladí lidé	mladý státy mladé státy	mladý ženy mladé ženy	mladý zvířata mladá zvířata
	Genitive	mladejch lidí mladých lidí	mladejch států mladých států	mladejch žen mladých žen	mladejch zvířat mladých zvířat
	Dative	mladejm lidem mladým lidem	mladejm státům mladým státům	mladejm ženám mladým ženám	mladejm zvířatům mladým zvířatům
	Accusative	mladý lidi mladé lidi	mladý státy mladé státy	mladý ženy mladé ženy	mladý zvířata mladá zvířata
	Vocative	mladý lidi! mladí lidé!	mladý státy! mladé státy!	mladý ženy! mladé ženy!	mladý zvířata! mladá zvířata!
	Locative	mladejch lidech mladých lidech	mladejch státech mladých státech	mladejch ženách mladých ženách	mladejch zvířatech mladých zvířatech
	Instrumental	mladejma lidma mladými lidmi	mladejma státama mladými státy	mladejma ženama mladými ženami	mladejma zvířatama mladými zvířaty

mladý člověk – young man/person, mladí lidé – young people, mladý stát – young state, mladá žena – young woman, mladé zvíře – young animal

This is an example of typical declension patterns used in Prague

Prague

Prague is the capital and largest city of the Czech Republic. Situated in the north-west of the country on the Vltava river, the city is home to about 1.3 million people, while its metropolitan area is estimated to have a population of over 2.3 million...

. There can be some small differences in individual regions.