vážit si + Genitive

The verb vážit si is a highly frequent, standard expression used to convey genuine regard, respect, or appreciation for a person, an abstract concept, or an action.

Grammatical Structure:

• Reflexive 'si': You must include the dative reflexive pronoun si. Without it, the verb vážit generally means 'to weigh' (e.g., vážit maso - to weigh meat). Note: You might occasionally see vážit si with an accusative object (e.g., vážím si maso), but this just literally means 'I am weighing meat for myself.'
• Genitive Case: The object being appreciated must be in the genitive case. Do not use the accusative, even though English uses a direct object.
• The Pronoun Trap: For most masculine animate nouns and many personal pronouns (like mě, tě, ho), the genitive and accusative forms are identical, which can mask the genitive requirement. To prove the case, use the 'Ona' test: substitute the feminine pronoun ona. In standard Czech, you must say Vážím si jí (genitive). However, you will frequently hear native speakers use the accusative form Vážím si ji. Note that this is a common grammatical mistake (often due to defaulting to the accusative or confusion with verbs like cenit si) rather than a valid casual variant.
• Reason for Appreciation: To express why you appreciate someone or something, use the preposition za or pro followed by the accusative case: Vážím si tě za tvou pomoc (I appreciate you for your help) or Vážím si tě pro tvůj charakter (I respect you for your character).
• Respecting Oneself: Because the verb already requires the dative reflexive si, learners frequently get confused about how to express respecting oneself. You must use the genitive full reflexive pronoun sebe (often paired with sám): Vážím si sám sebe (I respect myself).
• Questions: When asking what or whom someone appreciates, you must use the genitive interrogative pronouns koho or čeho. English speakers often mistakenly ask Co si vážíš? (accusative), but the correct form is Koho si vážíš? (Whom do you respect?) or Čeho si vážíš? (What do you appreciate?).
• Negation: The negative form nevážit si (to not respect / not appreciate) also strictly requires the genitive case (e.g., Neváží si mé práce - He does not appreciate my work).
• Clauses: When appreciating a fact or action expressed by a subordinate clause, use the genitive demonstrative toho: Vážím si toho, že... (I appreciate the fact that...).
• Verbal Aspect: The verb vážit si is strictly imperfective and has no direct perfective equivalent. To express a completed change of state, you must use a phase verb, such as začít si vážit (to start appreciating) or naučit se vážit si (to learn to appreciate). To express a single, completed act of appreciation, Czechs typically switch to the perfective verb ocenit, which takes the accusative case (e.g., Ocenil mou pomoc - He appreciated my help).

Adverbs of Degree:
This verb strongly collocates with adverbs of degree. To say 'I appreciate it very much', you will often place adverbs like velmi, moc, or hluboce right before the verb (e.g., Moc si toho vážím / Velmi si vás vážím), though Czech word order is flexible and they can also appear at the end of the clause for emphasis.

Important Distinctions:
Do not confuse vážit si with its close synonym cenit si (to value). While vážit si strictly requires the genitive, cenit si is more flexible and can take either the genitive or the accusative (e.g., cením si její statečnosti vs. cením si její statečnost). The genitive after vážit si is a fixed lexical rule that must be memorized.