Next to _-en_, many plural nouns end in _-s_.
The formula for the plural form:
noun + _s_
Examples of plural nouns that end in -s:
de tafel | de tafel s | the table(s)
de computer | de computer s | the computer(s)
de tovenaar | de tovenaar s | the wizard(s)
Apostrophe
When a singular noun ends in a single vowel, you cannot simply add - _s_ to it. After all, a single open vowel is a [long vowel](#/lesson/SpellingAndPronunciation.09). If we add - _s_ to it, it will turn into a (closed) [short vowel](#/lesson/SpellingAndPronunciation.13). In order to keep the vowel long, we add an [apostrophe](#/lesson/SpellingAndPronunciation.27):
de auto | de auto 's | the car(s)
het menu | de menu 's | the menu(s)
het programma | de programma 's | the program(s)
The single _e_ at the end of a word is an exception as it is a [mute e](#/lesson/SpellingAndPronunciation.17), not a long vowel. Adding s will not change the mute _e_.
het gebergte | de gebergte s | the mountain range(s)
de gewoonte | de gewoonte s | the habit(s), custom(s)
de boete | de boete s | the fine(s)
N.B. Correcting for [hard and soft consonants](#/lesson/SpellingAndPronunciation.23) is not necessary. An _f_ stays an _f_ and an _s_ stays an _s_.
Now you probably wonder why we need two different endings for the plural form. We already had _-en_, which does its job perfectly well. As with many other linguistic phenomena, there is no rationale behind it. It would have been a lot easier if we would just stick to only one ending. But since we have to deal with two, we might as well have a look at the '-s nouns' and the '-en nouns'.