[_Doen_, _zien_](#/lesson/Verbs.Ir10), [_gaan, slaan, staan_](#/lesson/Verbs.Ir11)
What do these verbs have in common?
The similarity between _gaan_ (to go), _slaan_ (to hit) and _staan_ (to stand) is obvious. Less obvious seems the presence of _zien_ (to see) and _doen_ (to do) in this group.
In fact, all these verbs have a regular [present tense](#/lesson/Verbs.Re07), which means they have no business being mentioned in the current topic about _completely_ irregular verbs.
I chose to mention them here anyway, because their infinitives do not allow us to simply follow the usual steps for deriving [the verb stem](#/lesson/Verbs.Re02).
Stem = infinitive minus '-en'
The first thing you learn about the stem, is that it is the infinitive minus _-en._ It is not difficult to see that this is impossible for the verbs _gaan, slaan,_ and _staan._
The same goes for _doen_ and _zien._ Although they both end in _-en,_ the letter _e_ is part of a [vowel combination](#/lesson/SpellingAndPronunciation.12), not the usual [mute _e_](#/lesson/SpellingAndPronunciation.17) you find at the end of an infinitive.
Because _oe_ in _doen_ and _ie_ in _zien_ are vowel combinations, they are each considered as _one_ long vowel. This is the reason why we cannot simply subtract _-en._
Stem = infinitive minus '-n'
So what do we do instead? Very simple: We subtract _-n._ So the stem of _zien_ is _zie,_ and that of _doen_ is _doe._
[Click here](#/lesson/Verbs.Ir10) to see the conjugations of _doen_ and _zien._
But the stem of _gaan_ is not _gaa!_ And _staa_ and _slaa_ are also wrong. Recall, that a [syllable never ends in a double vowel](#/lesson/SpellingAndPronunciation.11)! The stems are thus _ga, sla,_ and _sta._ In the 2nd and 3rd singular, however, we write double _aa_ again: _gaat, slaat,_ and _staat._ Because of the additional _t_ _,_ we need a double vowel to [keep the sound long](#/lesson/SpellingAndPronunciation.20).
[Click here](#/lesson/Verbs.Ir11) to see the conjugations of _gaan, slaan_ and _staan._