The Dual in Parts of the Body

01

Which Nouns

• oko - oči (eyes)
• ucho - uši (ears)
• ruka - ruce (hands, arms)
• noha - nohy (legs, feet)

• Mám jedna ústa, ale dvě uši.

  I have one mouth but two ears.

Note that oko and ucho are neuter in the singular, yet their plurals behave as feminine. The word changes gender when it goes plural, which nothing else in Czech does.

02

The Endings That Give It Away

The instrumental plural of all four ends in -ma rather than the usual -mi or -y, and ruka and noha also keep -ou in the genitive and locative plural.

• očima, ušima
• rukou, rukama, nohou, nohama

• Dívá se mi do očí.

  He is looking into my eyes.

• Vzal to oběma rukama.

  He took it with both hands.

03

Adjectives Follow

Anything agreeing with one of these nouns in the instrumental takes the same -ma ending. This is the one place in the language where an adjective ends that way, and it is a reliable sign that a dual noun is nearby.

• Má krásnou tvář s krásnýma očima.

  She has a lovely face with lovely eyes.

04

The Nominative and Accusative

The subject and object forms look like ordinary plurals and cause no trouble; it is only the three remaining cases that keep the old shapes. This is why a learner can use these words for a long time before meeting the dual at all.

• Umyj si ruce.

  Wash your hands.

05

Only the Body

The dual endings belong to these nouns as body parts and nowhere else. Used in another sense - the handle of a cup, the ear of a jug - the same word takes ordinary plural endings.

• Zlomil jsem si ruku.

  I broke my arm.

06

Counting Them

Because these nouns come in twos, the number two is what usually stands in front of them, and it has its own gender forms. The feminine and neuter dvě serves for oči and uši, which behave as feminine in the plural.

• Mám dvě uši.

  I have two ears.

• Musím si vybrat mezi dvěma možnostmi.

  I have to choose between two options.

07

Both

The word for both, oba, is itself an old dual and has only two gender forms: oba for masculine and obě for feminine and neuter.

• Oba se mýlíte.

  You're both wrong.