Breakdown of Он является известным экспертом.
он
he / it (for a masculine noun) / it (for a neuter noun)
известный
famous
являться
to be (formal)
эксперт
expert
Questions & Answers about Он является известным экспертом.
Why use является here instead of just a dash, like in Он — известный эксперт?
In Russian, the present-tense verb "to be" is usually dropped. However, являться is a special verb used in formal, official, journalistic, or academic contexts to mean "to be." It translates closely to "serves as" or "constitutes." For everyday conversation, Он — известный эксперт is exactly what you would say!
Why are известным and экспертом in the Instrumental case here instead of the Nominative?
The verb являться (along with other verbs of seeming and being, like казаться) always forces the noun and adjective that follow it into the Instrumental case. This is why we use the masculine Instrumental noun ending -ом (экспертом) and the matching hard-stem adjective ending -ым (известным).
является has the reflexive ending -ся. Does that mean he is doing something to himself?
Historically, yes! The base verb являть means "to show" or "to display." Adding -ся makes it "to show oneself [as]." While являться is now just the formal way to say "to be," thinking of it as "shows himself as" is a great trick to remember why it requires the Instrumental case.
Can I use является in everyday conversation to sound more fluent?