This is the 11188th most frequent German word.
sergey
The word "Sergey" is not German; it is a Russian male first name. In German, it has no specific meaning.
In this sentence, 'Sergey' is used as a proper noun, a personal name, and the subject of the sentence.
Sergey ist ein begabter Musiker.
Sergey is a talented musician.
Here, 'Sergey' functions as a proper noun and is used as the direct object of the verb 'gefragt' (asked).
Ich habe Sergey gefragt, ob er teilnehmen möchte.
I asked Sergey if he would like to participate.
In this instance, 'Sergey' is a proper noun and is used as a possessive to indicate 'Sergey's friends'.