Objects of Action Nouns

When you turn a transitive verb into a verbal noun, a coordinated morphological change happens:

• The Object: Drops its accusative -t marker. It takes either the nominative (unmarked) or the dative case (-nak/-nek), which are the standard possessor cases. Crucially, if the dative possessor is used, it structurally precedes the determiner (e.g., a háznak a felépítése or a problémának egy lehetséges megoldása).
• The Action Noun: Acts as the "possessee" and takes a possessive suffix that agrees with the person and number of the object, whether it is a noun or a pronoun (e.g., 3rd person -a/-e for nouns and 3rd person pronouns like az ő meghívása, or 1st/2nd person for pronouns, like a meghívásod for "inviting you"). Note that this form is ambiguous and can mean "inviting you" (objective genitive) or "your inviting [someone else]" (subjective genitive), depending entirely on context. The underlying object converts into a possessor pronoun (te in nominative or neked in dative), which is then dropped due to standard pro-drop rules unless emphasized or contrasted. Nominative possessors strictly belong after the determiner (e.g., a TE meghívásod). Dative possessors structurally belong before the determiner (e.g., NEKED a meghívásod) or move out of the noun phrase entirely. This position is dictated by the case, not the emphasis, though the choice to use the dative case itself is often motivated by a desire to emphasize or topicalize the possessor. Lexical plural nouns take a SINGULAR possessive suffix (e.g., a fiúk meghívása, never a fiúk meghívásuk), whereas plural pronouns take a PLURAL suffix (a meghívásuk).
• The Agent: The person performing the action must be expressed using adjectivized forms like általi, által való, or the very common dummy participle történő (e.g., Péter általi, Péter által való, or Péter által történő), not the bare postposition által, because a bare postpositional phrase cannot directly modify a noun.
• Oblique Objects: Verbs that take oblique objects (dative, instrumental, sublative, etc., such as segít valakinek) do NOT turn their objects into possessors. These objects retain their original case and usually connect to the verbal noun using participles like való or történő (e.g., a fiúnak való segítés).
• Verbal Prefixes: Verbal prefixes remain attached to the verbal noun, preserving the completed aspect, unless negated. In the negative, the particles nem or sem (neither/nor/not even) split the prefix and the verbal noun (e.g., a ház fel nem építése, a ház fel sem építése). Furthermore, when a verbal noun forms a compound with a generic bare object (noun incorporation), the verbal prefix is typically dropped (e.g., levelet ír meg becomes levélírás, not levélmegírás).

Crucial Distinctions:
1. Not an English Gerund: Because these are true nouns, they must be modified by adjectives, not adverbs (e.g., a ház gyors felépítése = "the quick building of the house", never gyorsan felépítése).
2. Versus Noun Incorporation: Noun incorporation (e.g., levélírás "letter-writing") lacks the definite article, the accusative marker, and the possessive suffix, and is used for general activities. The possessive construction (a levél megírása) is used for specific, referential events.
3. Versus Infinitives: An infinitive retains its verbal properties, does take an accusative object, and is modified by adverbs (e.g., a házat gyorsan felépíteni "to build the house quickly").
4. The 'My Doing' Trap: English speakers often use the possessive to mark the agent ("my building of the house"), but in Hungarian, you cannot say a ház felépítésem. The suffix must agree with the object (the house, 3rd person), and the agent is relegated to the által phrase (e.g., a ház általam való felépítése).
5. Intransitive Verbs: For intransitive verbs, the possessive suffix naturally marks the subject (e.g., Péter futása = "Peter's running"). This helps explain why the transitive object behaves the way it does: it occupies the single available possessor slot on the noun.