´ -> acute accent, generally used to denote open sounds like in
café (coffee). Here the 'e' has the same sound as the english 'e' in 'yes'. It's the most important accent we have, especially because it's also used to denote the strong syllabes of the words like in
sofá (couch),
difícil (hard) and
médico (doctor). If there is an acute accent, then the syllable which contains the accented letter is the strong syllable, and it has the open sound I explained above;
` -> grave accent, the only reason to use it is when you need to use 2 'a's at the same place in a sentence, one is a preposition and the other the female definite article like in
eu vou à praia (I'll go to the beach). If we didn't do it, the correct would be 'eu vou aa praia' like in its male counterpart
eu vou ao colégio (I'll go to school), where the 'a' is a preposition and the 'o' is the male definite article. At least here in Brazil more then half the people that graduated in College still don't know how to use the grave accent properly. This is the only accent here that has no sound meaning related to it. In spoken language you can't say when it should be used or not only by hearing;
^ -> circumflex accent, the opposite of the acute accent, generally denotes close sounds like in
você (you). I don't remember an english sound like that, but the 'a' sound is the closest one I remember like in 'take';
~ -> Tilde. Has only one purpose, and majorly appears in the conjunction 'ão' (extremely rarely as 'õe'). It makes a specific sound that combining the letters 'a' and 'o' only wouldn't make it, like in my previous example of
eu vou ao colégio, which has a different sound of
pão (bread). It's often translated to spanish like 'ón' and to english like 'ion'. E.g.
Mão (hand),
Avião (airplane),
Meditação (meditation),
Constituição (constitution);
ç -> c with cedilla, this is almost useless to our language, it only makes it harder. This has the same sound of the 's' sound I talked about earlier, and it could be perfectly substituted by the 'ss'. The previous example of
Meditação could be written 'Meditassão' and it would keep the same sound;
¨ -> diaeresis or diacritic. It was used to denote that the 'u' letter needed to be spoken instead of omitted. In the word
queijo (cheese), the 'u' has no sound, but in the word
conseqüência (consequence), the u does have a sound. But our grammars thought that this could be removed from our language, and for some years already this accent is dead.
BTW, we have no 'â'.
Which means Blade in english, and also means I was wrong
