From French to Italian
Italian is one of the closest languages to French, sharing a large number of cognates--that is, words from the same Latin root. Below are some tips for learning Italian if you already speak some French...also check out Jennifer's Indo-European Languages French and Italian Comparative Tutorial.
In many cases, the Italian word is the same as or similar to the French word, but with a vowel on the end (or pronouncing a vowel that is silent in French). Here are some examples:
Note that in many cases, consonant+L in French become consonant+I in Italian. e.g. plage-->spiagga, place-->piazza, fleur-->fiore, plante-->pianta...
Italian grammar is almost identical to French, with the same tenses and word order. In many cases, you can do a word-for-word translation and it will be grammatical. However, there are a few differences:
- No subject pronouns - Unlike French, Italian does not typically use subject pronouns. Thus, "Je parle italien" becomes "Parlo italiano" rather than "Io parlo italiano" (that version puts stress on the subject, rather like "Moi, je parle français"). Thus, questions are not formed by inverting the subject and verb: for example, "Parlez-vous italien?" becomes "Parla italiano?" (with only voice inflection making it a question).
- Vous becomes Lei or voi - While French vous can mean either plural or formal, Italian has Lei for formal singular "you" and voi for plural "you" (either formal or informal). However, since Lei is conjugated the same as he/she/it, there are no more conjugations to learn.
- More definitive articles - In general, Italian uses more definitive articles than French (or English). For example, in French you would start a sentence about your friend "Mon ami...", whereas in Italian you have to use a definitive article (the): "Il mio amico..." Word order is also somewhat more fluid than in French: for example, you could say "Il amico mio" which emphasizes that it's your friend.
- No pas - French ne becomes Italian non, but there isn't an equivalent to pas (Je ne parle pas anglais-->Non parlo l'inglese ...note also the extra article in Italian, as described in #3 above). The rest of the "negative" words (jamais-->mai, personne-->nessuno) all work the same way, though (Je ne vois personne-->Non vedo nessuno).
- No qui/que distinction for relative pronouns - This is a bit more in the weeds: Italian almost always uses che as a relative pronoun, even in cases where French uses qui. For example, C'est l'homme qui m'a donné l'argent becomes Questo è l'uomo che mi ha dato i soldi ...so basically "che" in Italian can mean "which" or "who"; chi either is used to ask "who?" or used in proverbs. Italian relative pronouns are explained in more detail on this site.
Obviously Italian pronunciation is different from French; usually this isn't a problem to keep straight, except when words are very similar. (In general, Italian pronunciation and spelling are more regular and straightforward than French...there is no Italian equivalent to Dictée!) For a few recent loanwords like terroir, champagne, and bijou, Italians keep the French pronunciation (or something closer to French than Italian).
- retourner --> tornare (not ritornare, which means "return again")
- l'état --> lo stato (not l'età, which means "age")
- ...lots more at Wiktionary (Italian wikipedia has the opposite way, also a nice list here)
Here are some useful "key" words that are used in more-or-less the same way as their French equivalents...master these words (plus a few verb conjugations including common irregular verbs like essere, avere, andare, potere, volere, dovere, sapere, and fare) and you'll be set!