English uses "when" for almost everything, but Dutch uses _toen_ for one moment or period in the past, and _als_ for "if" and for "when" in the present, the future or with repeated events. _Wanneer_ is a more formal "when" and also the question word. As linking words, all three send the verb to the end of their clause.
The pattern
_Toen_ looks back at one moment or period in the past; _als_ sets up a condition, a present or future moment, or a habit. _Wanneer_ is the formal twin of _als_ and also the question word.
- _toen_ + a past form, for one occasion or one period: _Toen ik in Leiden woonde, ..._
- _als_ for "if": _Als ik tijd heb, bel ik je._
- _als_ for "when" in the present or future, and for events that repeat, even in the past: _Als het regent, neemt Bas de bus._
- _wanneer_ in a direct question, followed by the verb: _Wanneer begint de les?_
- As linking words, all three start a [subordinate clause](#/lesson/subordinate-clauses) (a part of a sentence that cannot stand alone), so the conjugated verb (the one that matches the subject) goes to the end. A main clause after it [starts with its verb](#/lesson/subclause-first).
Examples
| Toen Mei vijf jaar geleden naar Nederland kwam, sprak ze nog geen Nederlands. | When Mei came to the Netherlands five years ago, she didn't speak any Dutch yet. |
|---|---|
| Ik stond net onder de douche, toen de bel ging. | I was just in the shower when the doorbell rang. |
| Als Emma morgen niet kan, verplaatsen we de vergadering. | If Emma can't make it tomorrow, we'll move the meeting. |
| Als Sanne thuiskomt, gaan we eten. | When Sanne gets home, we'll have dinner. |
| Als Joris naar zijn werk fietst, luistert hij altijd naar een podcast. | When Joris cycles to work, he always listens to a podcast. |
| Als we vroeger bij opa logeerden, mochten we lang opblijven. | When we stayed at Grandpa's back then, we were allowed to stay up late. |
| Wanneer u verhuist, moet u dit doorgeven aan de gemeente. | When you move house, you have to report it to the municipality. |
| Weet jij wanneer de huisartsenpraktijk weer open is? | Do you know when the GP's practice is open again? |
Why it works this way
English "when" does two jobs. Sometimes it points at one spot on the timeline: that is _toen_. Sometimes it sets up a condition or a pattern (whenever this, then that): that is _als_, which is why _als_ covers "if" and "when" alike. _Als Sanne thuiskomt_ (she will) and _als het morgen regent_ (it might) feel different in English, but Dutch treats both as the setting for the main clause.
Compare:
- _Toen het vorige week sneeuwde, nam ik de trein._ One week, one time.
- _Als het vroeger sneeuwde, nam ik de trein._ Every time it snowed.
- _Toen Daan belde, zat ik bij de tandarts._ One call, already over.
- _Als Daan belt, zeg dan dat ik bij de tandarts zit._ A call that may still come.
_Toen_ has a second job: at the start of a main clause it means "then", and the verb follows straight away: _Ik kwam thuis. Toen belde ik Lotte._ Compare _Toen ik thuiskwam, belde ik Lotte._
German speakers, careful: German "als" is Dutch _toen_, and German "wenn" is Dutch _als_.
_Wanneer_ in a statement simply sounds more formal. Letters from the _gemeente_ use it a lot, often meaning "if" (_Wanneer u vragen heeft, kunt u ons bellen._), while at the kitchen table most people say _als_.
Remember: asking when something happens? _wanneer_. One moment or period in the past? _toen_. A condition, a present or future moment, or a habit? _als_ (or _wanneer_ in formal Dutch).
Watch out
- Not: _Als ik gisteren thuiskwam, was het pakket er al._ Say: _Toen ik gisteren thuiskwam, was het pakket er al._ (one moment in the past needs _toen_)
- Not: _Als ik heb tijd, bel ik je._ Say: _Als ik tijd heb, bel ik je._ (the verb goes to the end of the _als_ clause)
- Not: _Toen ik in Amsterdam woonde, ik had geen auto._ Say: _Toen ik in Amsterdam woonde, had ik geen auto._ (after the _toen_ clause, the main clause starts with its verb)
- Not: _Ik weet niet als Carlos morgen komt._ Say: _Ik weet niet of Carlos morgen komt._ ("if" in the sense of "whether" is _of_)
Quick check
- Fill in _toen_, _als_ or _wanneer_: ... ik vorige week in Rotterdam was, kwam ik Fatima tegen.
- Choose _toen_ or _als_: ... het morgen regent, neem ik de trein naar mijn werk.
- Fix the sentence: _Toen Ahmed was ziek, bleef hij thuis._
- Choose _toen_, _als_ or _wanneer_: ... begint de cursus Nederlands?
Answers
- _Toen_: one moment in the past (last week).
- _Als_: a condition about tomorrow, and _toen_ only looks back at the past.
- _Toen Ahmed ziek was, bleef hij thuis._ The verb _was_ goes to the end of the _toen_ clause.
- _Wanneer_: of the three, only the question word can start a direct question.
Use it today
Write three sentences about your first weeks in the Netherlands that start with _Toen ik ..._, then one plan for this weekend that starts with _Als het mooi weer is, ..._. Check that the verb sits at the end of each _toen_ or _als_ clause.