What is the meaning of Być?

to be, to exist

to be [+nominative or instrumental]

to be [+adjective]

in future tense, forms the compound future tense of imperfective verbs [+infinitive]

in present tense, forms the compound past tense [+past participle]

in past tense, forms the pluperfect tense [+past participle]

in aorist, forms the conditional mood [+past participle]

to be indicates sameness or membership in a class [+nominative or instrumental]

to be auxilary verb used for predication [+adjective]

in future tense, forms future tense of imperfective verbs [+infinitive or verb in past tense]

in past tense, forms pluperfect tense [+verb in past tense]

to be indicates location, there be

to be [+nominative or instrumental]

to be [+adjective]

in future tense, forms future tense of imperfective verbs [+infinitive or verb in past tense]

in past tense, forms pluperfect tense [+verb in past tense]

to be

Source: wiktionary.org