As a language, English is relatively accent-free, although that wasn’t always the case. Until fairly recently, we still used diaresis in words like cöordinate and naïve, although that has fallen out of fashion and my spellchecker is insisting that the first word is wrong. The only English word I can think of off the top of my head to use any sort of marking is façade — but we borrowed that one as-is from French.
If you’re a fan of Shakespeare, you may occasionally see advisory accent marks in the text for very good reason: Pronunciation has changed since the Bard invented modern English. In his time, the last syllable of past participles was pronounced, so that the word “pronounced” would have actually been three-syllables — “pronoun-sed.” Nowadays, that –ed ending generally comes across as sounding like a single “d” or “t” is stuck on the end of the word. In Shapespeare’s day, “looked” would sound like “luke-id.” Now, it sounds like “lookt.”
So if you’re reading Shakespeare and see a word rendered like lovéd, it means to pronounce that last syllable as its own. Conversely, if the text isn’t marked like that but you occasionally see “lov’d,” then it means the syllable is pronounced by default and elided when marked with an apostrophe.
The lack of accents in English can be problematic because where we place emphasis in words almost seems arbitrary and, in fact, someone who otherwise sounds like they’re from the U.S. can give themselves away as Canadian by putting the emphásis in a place where we don’t normally hear it, and vice versa. A classic U.S. vs. UK example is the word “laboratory,” where the U.S. stresses the first syllable and the UK stresses the second, although at least the accents overall are a bigger giveaway of someone’s origin.
This is one of those areas where languages that use accents have a big advantage, especially if they have simple and consistent rules for where emphasis belongs. For example, in Spanish there’s what English speakers call the NOSE rule. If a word ends in N, S, or any vowel, than the natural emphasis is on the next-to-last syllable. If it ends in any other consonant, then the emphasis is on the last syllable. The accent marks are there to indicate deviations.
For example, the word for English is inglés. Without that accent, the stress would be on the first syllable because it’s the penultimate one and the word ends in S. Likewise, corazón, “heart,” has that accent there because otherwise the emphasis would be on the A. Unlike French, you can only have one accent mark per Spanish word, although you can have other markings, such as the tilde and diaresis along with accents. The Mexican director Alejandro Iñárritu’s last name is a perfect example of this.
As for diaresis, it’s rare in Spanish but it does happen, and one of my favorite examples is the word for penguin, pingüino. Without that mark over the U, the word would be pronounced “pin-GHEE-no,” with the second syllable the same as the gui in guitar. With it, it’s pronounced “pin-goo-EE-no.” It’s a subtle distinction, but important. This accent only appears over the letter U in Spanish.
Finally, there’s the tilde, that little squiggle above the letter N — and only above the N. In fact, Ñ and ñ are still considered separate letters from N and n in Spanish. This is the last holdout after revisions made in the 90s. Before that, Ch, Ll, and Rr were also considered letters on their own, but have since been removed, reducing the alphabet from 30 to 27 letters. (If you happen to have a Spanish dictionary or grammar that does include all 30 letters in the alphabet, you might want to toss it and get something more up-to-date.)
As for other languages, German is famous for its umlauts, which is the same thing visually as diaresis, and you can find them over the letters A, O, and U. The effect is basically like trying to pronounce the base vowel while shaping your lips into the form they’d make saying the letter E. Oddly enough, the end effect is more like you’re blending the vowel into the letter R. A famous example is the beer brand Löwenbräu, which sounds more like “Lervenbrye” because of those marks.
The other famous German letter, though not an accent, is the Eszett, or ß which, despite its appearance, is not pronounced as the letter B. Rather, it represents a double S sound, and it’s often replaced with those letters when German words are rendered in English documents, so that a word like “heiße,” which means hot, becomes “heisse,” which is technically wrong. Then again, so is writing “senor” instead of “señor,” but since most English keyboards don’t accommodate these characters easily, it’s hard to avoid.
Believe it or not, the Eszett sort of has a relative in English in the form of a lost letter known as the Long S. If you’ve ever looked at handwritten documents from the 18th Century and earlier, then you’ve probably seen it. It is eʃsentially a replacement for the initial lowercase S in a pair or a solo S in the middle of a word, but can easily be mistaken for a lowercase F. Other languages have similar variants in letters. For example, Arabic has different versions of letters depending on whether they’re at the beginning, middle, or end of a word, and Greek specifically has two different versions of its S, Sigma, one of which is only used at the end of a word. The Long S was basically killed off in the 1790s as foundries started to design new typefaces that favored what was originally called the Round S.
And this brings us around to the curious concept of Upper and Lower Case letters, in case (pun intended) you’ve ever wondered where those terms came from. Once upon a time, in the dark ages before digital layout, before photosetting, and before linotype, anything printed on a press was laid out by hand, and it was done with letters cast in lead. Generally, it was one letter per one piece of type, called a sort, although ligatures were common. These were combinations of letters frequently used together cast as one piece — ff, fi, fl, ffi, and ij were very common ligatures in English.
All of that type had to go somewhere to make it easy to pick and place quickly, so type cases were invented. These were literal wooden boxes with compartments in which the letters were sorted in a specific, though non-alphabetic order, although those orders varied from place to place. On top of that sorting, capital letters were kept in a separate case from miniscule letters, and the former was generally stored above the latter.
And there you go. The capital, or majuscule, type was kept in the upper case, and the miniscule letters were kept in the lower, and although physical typesetting like this has long since gone by the wayside, the terminology — like the legacy accent marks in English — linger on as an echo of history.