Seri
The Seri language of northwestern Mexico has infinitival forms which are used in two constructions (with the verb meaning 'want' and with the verb meaning 'be able'). The infinitive is formed by adding a prefix to the stem: either iha- (plus a vowel change of certain vowel-initial stems) if the complement clause is transitive, or ica- (and no vowel change) if the complement clause is intransitive. The infinitive shows agreement in number with the controlling subject. Examples are: icatax ihmiimzo 'I want to go', where icatax is the singular infinitive of the verb 'go' (singular root is -atax), and icalx hamiimcajc 'we want to go', where icalx is the plural infinitive. Examples of the transitive infinitive: ihaho 'to see it/him/her/them' (root -aho), and ihacta 'to look at it/him/her/them' (root -oocta).
Read more about this topic: Infinitive