Writers sometimes do not distinguish between an accent and an apostrophe.
An accent is a diacritic, a sign added to a letter. When you type a diacritic on the keyboard, the cursor does not move on and so the diacritic is added above (or in other cases below, by the side of or even inside) the letter. Examples of other diacritics are the circumflex ( ^ ), the umlaut ( ¨ ) and the tilde ( ~ ).
(Some Swedish words with diacritics have come into the English language, such as ångström, glögg, smörgåsbord and surströmming.)
English has two two accents, the acute accent ( ´ ) and the grave accent ( ` ).
The acute accent in English is used in loanwords such as apéritif, café, cliché, décor, fiancé and fiancée. In some very rare cases an acute accent is added to a loanword that lacks the accent to show that the last vowel of the word is pronounced: The Italian word latte (milk) is sometimes written latté (or lattè) in English.
The grave accent is rare in English and – like the acute accent – mainly used in foreign words: vis-à-vis, à la carte, ampère, manège, première.
Generally, English writers do not use diacritics even in loanwords – in fact, English keyboards do not have any accent marks. The Swedish words mentioned above are usually written as angstrom, smorgasbord, etc. There are, however, a few words in which the accent marks a difference between an English word and a loanword:
exposé (film or newspaper article revealing shocking facts about somebody) – expose (show, reveal, give experience)
résumé (short text giving the main points) – resume (start doing something again)
rosé (pink wine) – rose (a flower; pink colour)
The apostrophe is a punctuation mark. In English it has several uses:
It marks omission of one or more letters:
Don’t be late (Do not)! I’d prefer a smaller one (I would).
It marks the possessive case:
Have you seen my brother’s car?
There is no apostrophe in his, hers, its, ours, yours and theirs.
In the plural there is no s after the apostrophe:
Have you seen my brothers’ cars?
It marks plurals of single letters
Mind your p’s and q’s (Mind your manners; be careful about what you say or do).
In plurals of abbreviations and acronyms there is usually no apostrophe:
PCs, DVDs, MBAs, URLs, FAQs, UFOs, JPEGs.
If there are full stops in an abbreviation, you can include the apostrophe for clarity: Ph.D.’s.
Most style guides leave out the apostrophe in the plural form of decades:
They made their first record in the 1960s.
You can write an apostrophe before the decade when it is abbreviated:
Those born in the ’90s.
The apostrophe represents thousand:
30’ (= 30 000)
The apostrophe is also used as a quotation mark. British English prefers single quotation marks, while American English has double quotation marks ( ” ).
To sum up, you can do very well without the accent in English and only need to worry about the apostrophe. Remember to mind your p’s and q’s; skip the accent and put the apostrophe in the right place!