In Dutch, we use the apostrophe in the following cases:
To show that a letter has been omitted
zo'n | (zo een) | such a
'n | (een) | a, an
't | (het) | it
m'n | (mijn) | my
z'n | (zijn) | his
A'dam | (Amsterdam) | Amsterdam
's avonds | (des avonds\*) | in the evening
's winters | (des winters\*) | in the winter
's Gravenhage | (des Gravenhage\*) | The Hague
(\*) _des_ is an old-fashioned Dutch form of "of the", which we do not use anymore. We still use it in some common expressions, but mostly in abbreviated form with an apostrophe. Those of you who know German will recognize the 2nd declension here.
To keep a vowel long when adding -s to a noun
If a noun ends in an unstressed vowel, its plural gets -s at the end. To
[keep the long vowel long](#/lesson/SpellingAndPronunciation.19), we use an apostrophe. Recall, that if a single vowel sits in a syllable that ends in one or more consonants, it is a [short vowel](#/lesson/SpellingAndPronunciation.13)).
collega's | colleagues | alibi's | alibis
baby's | babies | accu's | storage batteries
Not all vowels need an apostrophe to remain long:
logés | (overnight) guests | coupés | train compartments
The acute accent already tells us that the vowel is long - we do not need to keep it long by adding an apostrophe.
schaapjes | (little) sheep | bloemetjes | (little) flowers
The [mute _e_](#/lesson/SpellingAndPronunciation.17) at the end of _schaapje_ is pronounced as English _the_. The sound does not change by adding the letter _s_: the _e_ is still mute.