не + Past Tense

To express that an action did not happen in the past, Ukrainian uses the negative particle не.

1. Placement and Spelling
The particle не is almost always written as a separate word and placed directly before the verb. For example: я не знав (I did not know).

Spelling Exceptions and Rules:

• Verbs that cannot exist without 'не': Some verbs are always written as one word because the root does not exist independently, such as ненавидіти (to hate) — він ненавидів.
• The prefix 'недо-': When 'не' is part of the prefix недо- (indicating insufficiency), it is written as one word, e.g., він недочув (he didn't hear fully/clearly or he is hard of hearing).
• Meaning-dependent spelling: Some verbs are written together or separately depending on their meaning. For example, нездужати (to be ill) is one word, but не здужати (to be unable to overcome/lift) is two words. Similarly, непокоїти (to disturb/worry) vs. не покоїти (not to rest), or неславити (to disgrace) vs. не славити (not to praise).
• Reflexive verbs: The particle не is placed before the verb just as with non-reflexive verbs: я не сміявся (I didn't laugh).

2. Aspect and Meaning
The meaning of the negation depends on the verb's aspect:

• Negating an imperfective verb usually means the process wasn't happening or a habit didn't exist (e.g., він не читав - he wasn't reading/didn't used to read).
• Negating a perfective verb means the result was not achieved (e.g., він не прочитав - he didn't read it).

3. The Genitive of Negation
When you negate a verb, the direct object often shifts from the Accusative case to the Genitive case. This is especially common with abstract nouns or when emphasizing total absence. However, in modern Ukrainian, the Accusative case is also perfectly acceptable and frequently used for specific, concrete inanimate objects. For example: я не бачив фільму (Genitive) or я не бачив фільм (Accusative) for 'I didn't see the movie'.

4. Double Negation
Ukrainian requires negative concord. If you use words like 'nothing' (ніщо) or 'never' (ніколи), you must still include не before the verb.

The Preposition Sandwich: When using negative pronouns with a preposition, the preposition must be placed between the ні- and the pronoun. For example, instead of saying 'з ніким', you must say ні з ким (with no one).

5. Existential, Possessive, and Identity Negation

• Absence and Lack of Possession: To express that someone or something was not present, or to express a lack of possession in the past, Ukrainian uses the Genitive construction. In this specific construction, the Genitive case is mandatory. The verb stays in the neuter singular не було regardless of the subject's gender or number: Його не було вдома (He wasn't home) or У мене не було часу (I didn't have time). This не було is the direct past-tense equivalent of the present-tense word немає. Note that unlike немає, не було is always written as two separate words.
• Active Possession: Alternatively, you can express lack of possession using the active verb мати (to have). In this case, the verb agrees with the subject (не мав, не мала, не мали), and the object is usually in the Accusative or Genitive case: Я не мав часу (I didn't have time).
• Identity/State: To say a person 'was not' a certain profession or 'was not' in a certain state, use бути with не. Here, the verb agrees with the subject, and the predicate is usually in the Instrumental case (though the Nominative case is also possible in certain contexts): Він не був лікарем (He wasn't a doctor), Вона не була щасливою (She wasn't happy).
  
  Pronunciation Note: When negating the past tense of бути, the stress in Ukrainian never shifts to the negative particle. It always remains on the verb: не був, не була, не було, не були.