lze + Infinitive

Register and Usage:
Lze is a staple of the "authorial stance" in formal writing. It is almost always paired with an infinitive verb, though the infinitive can occasionally be omitted if it is clearly understood from context (e.g., uděláme, co lze). Grammatically, sentences using lze are subjectless (jednočlenné věty). The infinitive does not act as the subject, but rather forms part of the predicate. While it typically backgrounds the person performing the action to keep the focus entirely on the action itself, the logical subject can be explicitly stated using the dative case (e.g., Nám nelze než souhlasit., though in this specific idiom the pronoun is usually dropped: Nelze než souhlasit.). Because it backgrounds the actor, it is very frequently translated into English using the passive voice (e.g., 'It can be verified' rather than 'One can verify it'). It is extremely frequent in written Czech (manuals, laws, academic papers) but sounds unnaturally stiff or robotic in everyday casual speech.

Morphology and Tense:

• Present: Stands alone without a copula (e.g., lze ověřit).
• Past/Future: Because lze is technically an adverb acting as a predicate (predikativum), it takes the default 3rd-person neuter singular of the verb to be (bylo lze, bude lze) for past and future tenses. However, these forms are practically obsolete in modern Czech and almost exclusively found in historical literature or highly stylized texts; modern Czech usually swaps to bylo možné or bude možné.
• Negation: The negative form is nelze (it is not possible to / one cannot).

Word Order and Clitics:
Lze and nelze often occupy the first position in a clause, in which case any second-position clitics (such as short pronouns) naturally follow them (e.g., Lze to ověřit.). However, they do not have to be in the first position (e.g., To už dnes nelze zjistit.).

Comparisons with Similar Patterns:

• Jde to: The direct informal/spoken equivalent. Learners often confuse the registers, using lze in casual speech (sounding overly formal) or jde in academic writing (sounding too colloquial).
• Dá se: The pattern dá se sits comfortably between the highly informal jde to and the highly formal lze. It is widely used in both spoken and standard written Czech. A crucial grammatical difference is that dá se is a reflexive passive construction, so the patient becomes the grammatical subject in the nominative case (e.g., Dá se přečíst ta kniha.). Because lze is subjectless, the patient remains the direct object in the accusative case (e.g., Lze přečíst tu knihu.). Additionally, when used with reflexive verbs, Czech simply drops one se (haplology), making phrases like dá se spolehnout perfectly grammatical and common. Crucially, do not carry the reflexive se over to lze; lze never takes se to form a passive meaning.
• Je možné: Semantically identical ("it is possible"), but requires the copula je and is slightly less formal, bridging both written and spoken Czech comfortably.
• Moci: The verb moci (can) usually takes a personal subject and conjugates, whereas lze is strictly impersonal.