Yes, we have "быть знакомым с" that means "familiarity with" a person/city or even some object or concept.
- Я знаю этого человека - I know this person. (factual knowing)
- Я знаком с этим человеком - I am familiar with this person
- Мы не знакомы - We don't know each other
- Мне не знакомо это место - I don't know this place
Is there anything like, for example in Czech, vědět - to know a fact - vím, že je pravda (i know it's true) and znát - to be familiar with something - znám toho muže (I know that man). I also wanted to ask, slightly off topic, if subject personal pronouns are compulsory in Russian, or can they be dropped sometimes?
To answer your second question, it is only partially pro-drop. For example just saying "читал книгу" it isn't clear who is doing the action as it could be я, ты, мы, вы. For present tense verbs conjugate more specifically and it can be okay to drop then. Not familiar with Czech but in Polish verbs conjugate very specifically in past tense, for gender as well as number, so it is much more easy to understand what is meant without pronouns.
One of the more advanced users mentioned - in another discussion - that pronouns are mandatory. That discussion concerned simpke sentences with pronouns in nominative form (eg "I buy bread"). I don't think he meant the dative form (as in "give me the bread"), since several other exercises left out "me".
"Официальный перевод имени — явная отсылка к персонажу сказки Киплинга «Рики-тики-тави», где королевскую кобру звали «Нагайна». В действительности, ту кобру также звали «Нагини» (у Киплинга почти все имена животных — просто названия их вида на хинди), но именно транслитерация «Нагайна» прижилась в русской литературе. Таким образом, авторская ассоциация с Киплинговской «королевской коброй» в переводе полностью сохранена."
(apparently it wants to clip off that last word from the URL, so you'll have to copy and paste)
Yes, I may have a nerdy side :p
In modern Russian negating a direct object of a verb does not trigger the switch to the Genitive automatically.
It does, for some verbs and some objects, it is rare for some others. The Genitive (when it does not sound old-fashioned) may give negation a bit more strength or imply less specific objects, as an extension.
Some abstract objects (e.g. "importance") tend to use the Genitive of negation in a lot of common combinations (e.g. "не вижу смысла", "не обращал внимания"). Иметь always uses a Genitive object when negated.
In general, the use of the Genitive with negated verbs is a complicated topic that is only touched in this course briefly.
No, because эту can only be used as a demonstrative adjective, i.e., эту змею can ONLY mean "this snake" (accusative case). To say "I don't know this is a snake" you must say, "Я не знаю, что это змея." The comma and the word что (meaning "that") are obligatory in standard Russian (whereas in English the word "that" is not, and the comma isn't used at all). Also, the word это in this case is a demonstrative pronoun meaning "this," unlike the word эту which can only be used as a demonstrative adjective (also этот, эта, etc.). Это causes a lot of confusion, but if you understand the difference between a demonstrative pronoun and a demonstrative adjective, AND understand that the word это does double duty as both, it makes it a lot easier.
f. not ending in soft sign, so 2nd declension.
snake/ crafty person -> animate.
Amongst the animate nouns, only the m. ones have the same gs. and as.
Accusative of 2nd declension: а -> у (eg книга) я -> ю (eg змея́)
On a side note, змея́ follows stress pattern d (stress in singular on ending, in plural on stem). So the as. is actually змею́.