The Dutch language lies, according to both the geographical position of the Netherlands and Belgium as well as for its linguistic properties, somewhere between German and English. Since a lot of Dutch people are in contact with the English language on a regular basis, we can quite safely assume that the Dutch language as it is used on by its speakers becomes more and more anglicised. The official grammar and spelling rules, however, can sometimes be much more like German. A good example of this is the way Dutch compound words should be written together according to the German-like rules, yet a lot of Dutch speakers write them apart due to what some call “the English space disease” (de Engelse spatieziekte).
Most Germanic languages – and English seems to be the exception to this – allow to form very long words. The possibilities are endless as you can combine compounds with other compounds, like hemelwater (rain water, literally: heaven’s water) and infiltratiegebied (infiltration area) leading to hemelwaterinfiltratiegebied as you can see in the picture above. Kindercarnavalsoptochtvoorbereidingswerkzaamheden is the longest Dutch word registrered by the Guiness Book of World Records and consists of the compound kindercarnavalsoptocht (children’s carnival procession) and voorbereidingswerkzaamheden (preparation activities). Likewise, we could make up the Dutch word kindercarnavalskledingwinkelbediende as a compound of kinder (children), carnaval (carnival), kleding (clothes), winkel (shop) and bediende (worker). In English, if such a compound were to exist, it would of course be written apart: children’s carnival clothing shopworker. Remarkably, shopworker in English is actually written together, but at the same time there is no clear explanation why this is the case for shopworker but not for shop assistant or railroad worker.
In English, compounds are usually seperated with a space, sometimes they are connected with a hyphen and rarely they form one word together. Fortunately, in Dutch the rules for writing words together (or not) are more straightforward (again, it is unknown why straightforward is written together and straight away is not), although a lot of Dutch people tend not to stick to the rules and this sometimes lead to misunderstandings (and language purists raising their eyebrows). The thumb rule in Dutch is that all nouns that together form a compound (two or more words that together form a new or different meaning), should be written together: messenslijper (messen + slijper, knife grinder), stoelpoot (stoel + poot, chair leg) and operatiekamer (operatie + kamer, operation room). This feature also allows you to distinguish between rodekool (a compound word for red cabbage) and rode kool (a cabbage that is just red).
Rodekool is a great example of the rule that adjectives that are part of a compound should be written together too. A good example of a misunderstanding due to mistakingly separating compound words would be minder jarigen (less birthday people) and minderjarigen (underage people). If you want to check if the adjective and the noun can be separated with a space, you should be able insert another adjective between them, such as mooi(e) (pretty). You’ll then see that design mooie keuken (design pretty kitchen), standaard mooie taal (standard pretty language), vol mooi bloed (full pretty blood) and minder mooie jarigen (less pretty birthday people) mean either nothing or something else you meant to say with mooie designkeuken (pretty design kitchen), mooie standaardtaal (pretty standard language), mooie volbloed (pretty full blood) and mooie minderjarigen (pretty underage people). There is however a grey area where this rule doesn’t seem to work and, surprisingly, the Dutch word for adjective, bijvoeglijk naamwoord, seems to be one of those exceptions to this rule. Moreover, adjectives derived from past and present participles, such as gelopen race (lit.: a run race) and lopend buffet (lit.: a walking buffet), can never be written together with the noun even though they form compounds.
It gets even more complicated when you create a compound of an adjective and a noun that are no compound on one hand and another noun on the other. We see this in lange afstand (long distance) and relatie (relationship) becoming langeafstandsrelatie (long-distance relationship), with the adjective and the two nouns written together in Dutch and combined with a hyphen in English. In Dutch this is is done because lange afstandsrelatie or written apart would mean a long-term distance relationship instead of the distance being long and for the same reason in English a hyphen is used. In Dutch, if you find such a combination of words written together unreadable, you are also allowed to separate them with a hyphen, but unlike English, this should be done with all words (lange-afstands-relatie). A hyphen is even mandatory when there is vowel colission, which occurs between double vowels and the Dutch vowel combinations of au, ei, eu, ie, ij, oe, ou and ui, like in auto-ongeluk (car accident), homo-emancipatie (homosexual emancipation) and taxi-examen (taxi exam).
In the word langeafstandsrelatie we also see the so-called tussen-s (between-s or inter-s). This interfix can be seen in a variety of Dutch words, like zonsopkomst (zon + s + opkomst, sunrise) and used to indicate the genitive (the rise of the sun). In English this can still be seen in compounds like baker’s wife and, hence, in Dutch this is written as bakkersvrouw (bakker + s + vrouw). Nevertheless you shouldn’t assume that whenever a genitive s is written in English compound words, the same will be the case for Dutch. Unfortunately, there are no clear rules that assign the genitive interfix s to compounds and many Dutch words actually are not written with s in between. What’s more, the insertion of the s might even vary from dialect to dialect or even from person to person, leading to both spellingfout as spellingsfout (spelling mistake) as correct. The Dutch language association Onze Taal (Our Language) therefore suggests that however you use this genetive s, do it consistently.
And as for the compound words? Just write them together or at least use a hyphen, and this I say to both native speakers and learners of the Dutch language.