WhenVBal: The verb of a when-clause obligatorily appears in base form.

(1) meg-ír-om a level-et és el-megy-ek vásárol-ni.

pref-write-prs.obj.1sg the letter-acc  and away-go-prs.1sg shop-inf

‘I’ll write this letter and then I’ll go shopping.’

(2) el-megy-ek vásárol-ni miután meg-ír-t-am a level-et.

away-go-prs.1sg shop-inf after pref-write-pst-1sg the letter-acc

‘I’ll go shopping after I finish the letter.’

In Hungarian, the verb form both in coordinated and subordinated when-clauses is identical with the base form (Kenesei et al. 1998: 48‒50, Haader 2000a: 504‒507).