Breakdown of Улыбка является очевидным признаком.
улыбка
smile
очевидный
obvious
являться
to be (formal)
признак
sign (indication, symptom)
Questions & Answers about Улыбка является очевидным признаком.
Why does this sentence use является for "is" instead of just using a dash?
While you can completely omit the "to be" verb in the present tense (using a dash), являться is used as a formal or written equivalent of "to be". You will see it often in news articles, scientific texts, and formal writing.
Why are the words очевидным признаком in the Instrumental case here?
The verb являться always requires the noun or adjective that follows it to be in the Instrumental case. It works similarly to быть (to be) in the past or future tense, but являться forces the Instrumental even in the present tense!
How do the case endings for очевидным признаком work here?
The base noun is признак (a masculine noun ending in a consonant), so it takes the standard masculine Instrumental ending -ом. The adjective очевидный takes the matching masculine Instrumental adjective ending -ым.
I've learned знак for "sign". How is признак different?
Знак refers to a literal, physical sign (like a traffic sign, a mathematical symbol, or a hand gesture). Признак means "sign" in the sense of an indication, trait, or symptom, like a smile being an indication of happiness, or a fever being a symptom of an illness.