Verb extensions in Kah consist of prefixed verbs altering the meaning of the verb they are attached to. This means that a single verb stem can be used to built new verbs from in a standardized manner. This method has proved to be a rich source of verbal derivation in many natural and constructed languages. For constructed languages the main benefit lies in the instant recognizability and logic it adds to the lexicon as well as the fact it keeps the minimum number of roots needed for a mature lexicon beneath acceptable perimeters.

Phonotactic rules

The phonotactic rules of verb extensions differ slightly from those of normal compounds. When a common verbal derivational prefix ending in a nasal stop (either -m, -n or -ng) is put in front of  f, v,h, l, r, a consonant combination (kw, sw and py) or another nasal stop, the final nasal is dropped:

jam + le  = jale                    (and not: *jamale)

mun + ren = muren          (and not: *munuren)

tom + reven = toreven     (and not: *tomoreven)

Reversive

The reversive extensions expressed the undoing of an action and is formed by prefixing the verb mon "to undo" to the original verb.  Compare:

Permissive

Permissive verbs are formed with the root  ten- expressing "to be able" and express something rather hard to describe. It denotes that an action or quality is possible, advisory or morally right.

Causative

A causative verbs express an action is caused to happen. The verb mun "to cause" is prefixed to the basic verb stem: