Masculine Inanimate Paradigms Compared

Czech masculine nouns split first by animacy (does it refer to a living being?) and then by whether the stem ends in a hard or soft consonant. This page pulls the two inanimate patterns together — the hard hrad type and the soft stroj type — and folds in the two lexical quirks that trip everyone up: the genitive-singular -u/-a split and the locative-singular -ě/-u split. Treat it as your one-stop reference once you have met the individual paradigms.

The single fact that defines this whole class, and separates it from animate masculines like pán and muž, is this: for inanimate masculines, the accusative is always identical to the nominative, singular and plural. There is no separate "object form." Hold on to that — it is the easiest win in the entire Czech case system.

The two base patterns

Hrad ("castle") ends in a hard consonant (-d), so it takes the hard endings. Stroj ("machine, device") ends in a soft consonant (-j), so it takes the soft endings. Almost every inanimate masculine noun belongs to one of these two, decided purely by the final consonant of the stem.

Notice how the soft pattern leans on -e/-i where the hard pattern leans on -u/-y/-ě. That is the whole hard/soft contrast in miniature.

The diagnostic cells

You do not need to memorize twelve forms per noun. Four cells tell you everything about which pattern (and which lexical option) a noun follows. If you can produce these four, the rest fall out automatically.

The genitive plural and accusative are not in the table because they are predictable: genitive plural is -ů for both (hradů, strojů), and the accusative simply copies the nominative.

The genitive-singular split: -u or -a?

Here is the first genuine difficulty, and it only affects the hard (hrad) type. Most hard inanimate masculines take -u in the genitive singular: hrad → hradu, stůl → stolu, autobus → autobusu. But a stubborn group of common, mostly native words takes -a instead: les → lesa (forest), chléb → chleba (bread), domov → domova (home), kostel → kostela (church), oběd → oběda (lunch), svět → světa (world), rybník → rybníka (pond).

There is no clean rule here. The -a group is a closed, historically determined list — you simply have to learn these high-frequency members as you meet them. The good news is that they are a minority; -u is the safe default when you have no other information.

The soft (stroj) type sidesteps this entirely: its genitive singular is always -e (stroje, čaje, pokoje), with no -u/-a choice to make.

The locative-singular split: -ě, -u, or -e?

The second difficulty, again confined to the hard type, is the locative singular after v, na, o, po, při. Two endings compete:

• -ě (-e) — the older, "place-like" ending, often with a consonant softening: hrad → na hradě, les → v lese, dvůr → na dvoře, kostel → v kostele. The hook on -ě triggers the change d → dě, t → tě, n → ně, while after s, z, l, r it surfaces as plain -e.
• -u — the newer, more abstract ending, standard after the velars k, g, h, ch (which cannot take -ě at all) and common with borrowed or technical words: vrh → ve vrhu, břeh → na břehu, and the irregular rok → v roce. Some nouns allow both — autobus → v autobuse / v autobusu are both heard.

The word rok ("year") is worth flagging on its own: its locative is the irregular v roce, not v roku — a form you will use constantly when giving dates.

The soft type, once again, is regular: its locative singular is always -i (o stroji, na kraji, v pokoji), the same as its dative.

The decision rule

Put it all together as a two-step routine for any inanimate masculine noun:

1. Look at the final consonant of the stem. Hard consonant (b, d, f, g, h, ch, k, l, m, n, p, r, s, t, v, z) → hrad type. Soft consonant (c, č, ď, j, ň, ř, š, ť, ž) → stroj type. (A handful of "ambiguous" consonants like l, s, z default to hard for these patterns.)
2. If it is the hrad type, additionally learn its genitive singular (-u or -a?) and its locative singular (-ě/-e or -u?). If it is the stroj type, you are done — the soft endings have no such choices.

The constant: accusative equals nominative

Whatever else differs, this never changes for inanimate masculines. Compare the two patterns in the accusative — they each simply repeat the nominative:

This is exactly where inanimate masculines part ways with animate ones. An animate masculine borrows its accusative from the genitive (vidím pána, "I see the gentleman"; znám muže, "I know the man"), which is the famous Czech animacy rule. Inanimates ignore it. So Vidím hrad ("I see the castle") keeps the bare nominative form, while Vidím pána changes. For the animate side of the picture, see the masculine animate summary and the animacy overview.

Common mistakes

The biggest English-speaker trap is conflating the inanimate types with the animate ones — applying the genitive-as-accusative rule to a castle or a machine because it "feels like a thing the verb acts on."

Forcing -a in the genitive where the noun actually takes -u:

Using regular -u for the irregular locative of rok:

Giving the soft (stroj) type a hard plural:

Key takeaways

For the full hard paradigm see hrad in detail; for the soft paradigm see stroj in detail. The two lexical splits get their own deep dives in the genitive split and the locative split.