"Caran d'Ache was the pseudonym of the 19th century French satirist and political cartoonist Emmanuel Poiré (November 6, 1858 – February 26, 1909). "Caran d'Ache" comes from the Russian word karandash (карандаш), meaning pencil, which in turn comes from the Turkish words kara taş, meaning black stone." https://en.wikipedia.org/wiki/Caran_d%27Ache
No, it's not an exception. «Ма́льчик» is masculine, so the usual genitive ending is -а (ма́льчик 'boy' — ма́льчика, стол 'table' — стола́) or я after soft consonants (учи́тель 'teacher' — учи́теля).
The ending -и is used for feminine words with stem ending in soft consonant or к/г/х/ш/ж/ч (да́ча 'dacha' — stem is дач- — genitive is дачи). Some masculine words can belong to feminine declension (notably short forms of names, like Ви́тя — stem is Вить- — genitive singular is Ви́ти), those words are exceptions. But «ма́льчик» is not.
No, there are 3 cases in total. :D Russian has 3 declensions:
- feminine a-declenstion (words engling in -а and -я in nominative singular; include some masculine words), e.g., вода́ 'water', во́ля 'freedom', свеча́ 'candle',
- masculine/neuter declension (words ending in consonants and -о or -е in nominative singular), e.g. слон 'elephant', гусь 'goose', яйцо́ 'egg', со́лнце 'sun',
- feminine i-declension (feminine words ending in soft consonant or шь/жь/чь in nominative singular), e.g. рожь 'rye'.
Masculine declension can also end in soft consonant, so it's sometimes difficult to distinguish between a masculine declension and a feminine i-declension.
Native speakers also find this difficult: at school, we paid speacial attention to remembering the correct gender of the words like гусь 'goose (masculine)' and на́дпись 'inscription (feminine)'. Also, they have a different gender in different languages (e.g. in Belarusian), so this suggests they have been a source of confusion for a while.
Also, sometimes words have a declension that is different from its gender. E.g. «па́па» 'dad' has a feminine declension, but it's masculine. Most short forms of names have feminine declension.
Ь (') doesn't make a sound in itself, but it changes the pronounciation of the previous sound. You can try to get this difference by comparing similar words: стол / stol — столь / stol', гол / gol — голь / gol'. I know getting the distiction might be hard, but with some practice you'll understand it.
In fact, in your sentence it changes the meaning! «У мальчика ест карандаш» means '[Something] is eating the boy's pencil'. Creepy!
I'm no Russian expert, so take this with a grain of salt.
У is never translated into 'the' or 'this'. 'The' simply doesn't exist as an independent word, and 'this' (and 'that') are taken care of by ЭТО and its variants. The У simply serves to remind you that the noun following, here МАМЫ, is in Genitive case, for it could be mistaken for Nominative plural.
With «есть» 'there is', you use nominative. With «нет» 'there is no', you use genitive.