Ability and Permission: moći, smeti, znati

English can compresses several meanings into one verb. Serbian normally separates моћи (be able / circumstances permit), смети (be allowed / dare), and знати (know how through learned skill). Choosing among them says why the action is possible, not merely that it is possible.

All three can take either an infinitive or a same-subject да + present complement. Aspect remains a separate choice inside that complement, and past or conditional forms require the l-participle to agree with the subject.

The Core Contrast

The first sentence contrasts physical ability with a restriction. The second contrasts a learned skill with present circumstances. English uses can in both halves; Serbian chooses a different modal because the source of possibility changes.

Compact Present Paradigms

Negation is regular and separate: не могу, не смем, не знам. A ли question places the particle after the finite modal.

The same affirmative-negative-question pattern works with смети and знати: смеш — не смеш — смеш ли, знаш — не знаш — знаш ли.

Моћи: Ability and Circumstantial Possibility

Use моћи for physical or mental capacity and for circumstances that enable or block an action.

In requests, могу ли...? and можеш ли...? extend from ability to practical permission or willingness. The context, not a separate form, supplies the polite reading.

The conditional могао бих / могла бих makes a request or suggestion less direct. The l-participle agrees with the speaker.

Смети: Permission, Prohibition, and Daring

Use смети when an authority, rule, safety constraint, or social norm licenses the action. Its negative is especially important: не смеш often means you must not, not merely you cannot.

Compare a blocked possibility with a prohibition:

Смети can also mean dare, especially in questions and negatives.

Whether this means fear or lack of permission comes from context. If ambiguity matters, state the source: родитељи ми не дозвољавају (my parents do not allow me) versus плашим се да му кажем (I am afraid to tell him).

Знати: Learned Know-How

With a verbal complement, знати can express an acquired skill. This is different from knowing a fact, as in Знам адресу, and from present circumstantial ability.

For skills, умети is also common and often more unambiguously means know how; the boundary and the contrast with познавати are treated in знати, познавати, and умети. Знати is nevertheless normal in everyday Serbian in expressions such as знам пливати / знам да пливам.

The first clause reports competence; the second reports a current obstacle. That contrast is exactly what English can leaves implicit.

Infinitive or да + Present

With the same understood subject, both constructions are standard Serbian.

The infinitive carries no person marking; да + present repeats the subject through the finite ending. A different expressed subject cannot simply be placed before an infinitive. Serbian uses another construction, often дозволити + dative + да-clause for permission.

Do not copy English They allowed the children to stay as a form of смети with an object. Смети describes the subject’s permission: Деца смеју да остану.

Tense, Mood, and Agreement

The present modal does not map mechanically onto English can. Serbian uses an agreeing l-participle in the perfect and conditional.

Past могао сам may describe capacity without saying whether the action actually occurred. To state successful completion, Serbian often uses a lexical perfective such as успео сам (I managed).

Modal l-participles and pronominal clitics obey ordinary second-position order. In бих ти га, conditional auxiliary бих precedes dative ти and accusative га.

Aspect Inside the Complement

The modal does not choose aspect for you. An imperfective complement presents an activity, repetition, or open process; a perfective complement presents a bounded result.

The permission is the same; користиш describes repeated use, while употребиш licenses one bounded use.

Practice Tasks

Task 1: Name the Source of Can

Express learned skill, current possibility, and permission in three clauses.

Task 2: Make the Past Form Agree

Say that a female speaker was able to stay but was not allowed to drive.

Common Mistakes

Using смети for physical inability

Using знати for a temporary opportunity

Forgetting participle gender

Copying an English object-plus-infinitive after смети

Making the modal choose aspect automatically

Key Takeaways

• Моћи expresses ability or circumstantial possibility; смети expresses permission, prohibition, or daring; знати can express learned know-how.
• Negative не смеш commonly means must not, whereas не можеш often means that circumstances make something impossible.
• Both infinitive and same-subject да + present complements are standard; a different subject requires a finite construction.
• Past and conditional forms use an agreeing l-participle: могао/могла сам, могао/могла бих.
• Modals do not fix the complement’s aspect; choose imperfective or perfective according to the event view.