Can anyone explain why 'she drinks water' does always include the definate article, 'she eats sugar' does not contain the definate article (duo says lei mangia zucchero) and 'she eats bread can be either 'lei mangia pane' or 'lei mangia il pane'. Very confused.. just got used to french from english...! Thanks in advance
When you use "drinks" (beve) while talking about "he" or "she" or "the man" etc. It is "beve" for example, Lui beve, Lei beve, L'uomo beve
Now, "drink" can mean either "bevo" or "bevi". When you use "drink" as in "I drink", you should use bevo (Io bevo)
When you use "drink" as in "you drink", you should use bevi (Tu bevi)
You use l + apostrophe to contract an article and when the word right after starts with a vowel. Think of it as using it is = It's. You'll contract 2 words into 1. The rule applies to an article and the word that starts with a vowel. To echo @gregors10's comment, it's a matter of flow where it "flows" in a more natural way by contracting words instead of pronouncing 2 words with similar sounds back to back. Hope that helps.
Be warned. Lei is the formal term for he or she, lei is the informal term for she; when a sentence starts with lei, it is of course written Lei and therefore can mean she (informal), she (formal) or he (formal), so there is no way to tell the sex when a sentence starts with Lei unless it is long enough for there to be another clue.
Your information is so wrong! Lei (capitalized) is NOT formal for he/she; there is no such thing. Lei (capitalized) is formal for “you. When not capitalized it means “she”. It never means “he” that is lui. Difficulty arises at the beginning of a sentence when capitalized it could mean you (formal) or she.