Inflection

All Czech nouns, adjectives, pronouns, verbs, numerals, and adverbs take different endings because of inflection. Nouns, adjectives, pronouns and numerals are declined, verbs conjugated, adjectives and adverbs have three degrees of comparison.

All declension can be hard or soft.
Czech has seven different cases: Nominative, Genitive, Dative, Accusative, Vocative, Prepositional, Instrumental.

The Nominative usually takes the position of a subject in a sentence. Doktor pracuje. Pes je starý. Studentka studuje. Okno je otevřené.

To make the nouns' and adjectives' declension easier, Czech grammar groups words by their gender -- Masculine, Feminine, Neuter (Masculine nouns are divided into two groups: Animate and Inanimate), and then by their ending in the Nominative -- hard or soft. So a given word might be a “hard masculine noun or “soft feminine adjective” etc. These categories are represented by chosen words called paradigms.

How to tell the Gender:

Nouns ending in -o and -í are Neuter.

Nouns ending in -a are usually Feminine: žena, maminka, třída, tužka, etc. Only a few are Masculine: for example předseda (chairman) or starosta (mayor). Some surnames with an -a ending are Masculine as well: Kundera, Klíma, Neruda, Kafka, etc.

Nouns ending in a consonant, be it hard, soft or ambiguous, are usually Masculine. However, some can be Feminine: píseň (song), báseň (poem), láhev (bottle), kost (bone), radost (joy), etc.
Nouns ending in -e or -ě can be of any gender.

Adjectives are either hard or soft. Hard Adjectives take -ý for Masculine, -á for Feminine and -é for Neuter Gender: dobrý, dobrá, dobré. Soft Adjectives take just -í for all genders: universitní, jižní, cizí (M+F+N).

The forms of the demonstrative pronoun ten, ta, to are different for each gender: ten (M), ta (F), to (N). This pronoun is often used as a definite article in Czech. It can also be translated as “this” or “that.”