Questions & Answers about Я знаю этого учёного.
Why does the word for 'this' (этого) end in '-ого' here?
Because the scientist is the direct object of the verb знаю (I know), the phrase needs to be in the Accusative case. In Russian, when a masculine noun is a living being (animate), its Accusative case endings look exactly like the Genitive case endings. That is why этот (this) changes to этого.
How do you pronounce the 'г' in этого?
It is pronounced like an English 'v'. In Russian, the grammatical endings -ого and -его are always pronounced with a 'v' sound instead of a 'g' sound.
Why does учёного have an adjective ending if it is a noun meaning 'scientist'?
The word учёный originally meant 'learned' (an adjective), but it is now used as a noun meaning 'scientist'. Because of its origins, it still takes adjective endings when it changes case. Its Accusative form here ends in -ого because a scientist is a living being, so it takes the Genitive-looking ending just like этого.
Can знаю be used for knowing both people and facts?
Yes! Unlike some languages that use two different verbs for knowing a person versus knowing a piece of information, Russian uses знать (where знаю is the 'I' form) for both situations.