What is the difference between the accents?
Examples: à and á or ô
The acute accent (l'accent aigu) goes above the letter e to change its pronunciation to something like "ay", like in café.
The grave accent (accent grave) goes above the letter e to change its pronunciation to something like "eh", like in crème.
If there is no accent, the pronunciation of "e" alone is either "uh", like in "le", "revoir", or silent (in most varieties of French), like in "mange", "parle".
The grave accent above a letter "a" (à) doesn't change its pronunciation, but distinguishes from "a"="has". It also goes above the letter u in "où = where" (this is the only word in French with an ù) to distinguish it from "ou = or".
The circumflex accent (l'accent circonflexe), or "the hat", can go above any vowel, and has a similar function to à and ù in that it doesn't usually change the pronunciation drastically, but it distinguishes words apart which are otherwise spelled the same: mur = wall, but mûr = ripe. Sometimes, the circumflex accent simply goes on a letter for historical reasons "hôpital", "même", "fenêtre" etc., which are too lengthy to explain here: Google is your friend :)
In short, sometimes you can hear which way the accent leans (on an e), but sometimes you simply have to memorize how a word is spelled!
PS: á doesn't exist in French
Excellent response! I would like to add a little something on the historical root of the words. The circumflex or "hat" appears to be used when the word in its root origin had an S after the vowel with said accent. E.g. Hôpital (hospital), "même" ("miSmo" in Spanish), fenêtre ("fineStra" in Italian), pâte (paSta).
I notice you forgot the most tricky accent in french: the Trema " ¨ " which can only be placed on " ë ", " ü " and " ï " (sometimes on " ÿ " but don't bother with this one, you only find it on francized names (places, last name ...)). The trema is rarely used in the language but you find it in some fairly used word like "Noël/Christmas" or "Maïs/Maize". It is most of the time used with two consecutive vowels which usually form a diphthong in french "oi/wa, œ..." but with the adding of the " ¨ " on the second vowel (always the second one) you break this diphthong in two dinstinct sounds : Noël is pronounced "No/èl or No/ayl"... I don't want to discourage anyone from learning french (I, myself, had to because that's my native language) but this peculiar accent is still the terror of any french pupils or any french learners. Good luck I, myself, have been struggling with the learning of the english language for almost 20 years !
Contrary to how most people feel about the language and its difficulty, I've been studying Chinese in college and it's become the easiest language I've ever learned, both writing and speaking it (hearing can still be pretty difficult). But I encourage more people to find somewhere they can learn the language.
Also, the "ç", personally i would like to see this in english. It makes the c sound like a s. for example, garçon, or ça. a c without the cedilla sounds like a "k". it is also the hardest accent to write if you are using pen and paper, many french teachers say to draw a little "5" under the c to make the cedilla.