In Italian, consonants can be divided into pure and impure sounds (or simple and complex sounds). While both types can occur anywhere in a word, they only really matter, grammatically speaking, at the beginning of masculine nouns.
Italian vowels are divided into two categories: hard and soft. Hard vowels (A, O, U) cause the consonant that precedes them to be pronounced with a hard sound, while soft vowels (E, I) are preceded by a soft sound.
Italian verbs that end in –care, –gare, and –cire require a small spelling change in certain conjugations. For the most part, these verbs are conjugated just like regular –are verbs, other than a little problem in some conjugations that must be corrected for reasons of pronunciation. It’s easy enough to do, once you understand why and how.
The distinction between tu and Lei is one of the most confounding aspects of Italian, and one of the most basic. The influence it has on verb conjugations and pronouns is considerable, but more than that, the choice of tu or Lei is a matter of etiquette.