Questions & Answers about Это самый опытный врач.
How does самый work in this sentence to mean 'the most'?
Самый is used with an adjective to form the superlative degree, meaning 'the most'. It acts like a regular adjective, so it must match the gender, number, and case of the noun it describes. Since врач is a masculine, nominative noun, both самый and опытный take the masculine endings (-ый).
Why do we use the neuter word Это when врач is a masculine noun?
Does the adjective опытный come from another Russian word?
Yes, it is built from the noun опыт, which means 'experience'. Adding the standard adjective ending -ный turns it into опытный (experienced).