1. The Russian alphabet is weird itself. Some characters are exactly like in the Latin alphabet, while others look the same, but sound different, and the two characters "ъ" and "ь" represent no sound, who needs them?
2. One character E may represent two different sounds [ye] and [yo].Actually, there is a special character for "yo" in Russian. It is Ё, but in order to make handwriting faster, people omit the two dots on top the Ё, so Ё turns into E. This is confusing.
3. Since "tovarisch" is no longer in use in Russia, there are no special words to address another person or many people. You may hear "дамы и господа" (ladies and gentlemen), but this is considered somewhat unnatural. People may use "мужчина"/"женщина" (man/woman), but that sounds a bit rude. Over the last two decades, Russians have not been able to decide what words would be best for addressing and select the ones each time according to the exact circumstances.
4. No "am/are/is". In Russian, the verb "to be" should be omitted in the present tense, however, in the past and future it should be used.
5. Russian word order is flexible, but it doesn't mean that you may put words in any order you like. The meaning of the sentence may change cardinally because of the word order. I.e. "Я иду домой" means "I'm going home", while "Я домой иду" means "It is home where I'm going to (not anywhere else)", and "Домой иду я" means "It is I, who is going home" (not you, not anyone else. The others are staying at the office and working!) So the word order in Russian depends on what exactly you want to say to others.
6. To change a sentence into a general question, one doesn't have to change anything, but intonation, i.e. "Ты дома." (you are at home) vs "Ты дома?" (Are you at home?)
7. The numbers 1 and 2 have genders while the rest numbers don't, i.e. "один мальчик" (one boy), "одна девочка" (one girl), but "три мальчика/девочки" (three boys/girls).
8. The number 1 (один) have a plural ("одни" = soli)
9. Verbs in the past tense have genders, while verbs in present and future tenses don't, i.e. "он играл" (he played), but "она играла" (she played), and "он играет" (he plays), "она играет" (she plays).
10. Russian nouns have animacy, that means that animate nouns are considered more alive than inanimate ones. So in Russian, a dead man (мертвец) is more alive than a corpse (труп), because a dead man (мертвец) is animate and a corpse is not.
What do you find most weird in the Russian language?