Appendix:Old Czech verbs

Infinitive and supine
Unlike modern Czech, Old Czech had two non-finite verb forms – infinitive, which probably originated as a dative form of some deverbal noun, and supine, which originated as an accusative form. The infinitive endings were -ti (vésti, státi) or -ci (péci). The supine forms had short ending vowels and their endings were -t (vest) or -c (pec), the only exception being verbs formed by contraction of a longer word (stojati –> státi) which didn't shorten their ending vowels in supine (stát).

Supine was used as an object of verbs of motion and mostly formed from imperfective verbs. If the supine verb had an object, it was usually in genitive.

Already in the 14th century, the infinitive ending -ti was sometimes reduced to -ť. In the 15th century, the supine disappeared completely and the infinitive had two possible endings -ti/-t with the -ti being formal and preferred until the second half of the 20th century when the ending -t became standard and -ti archaic.

Future
The future tense can be expressed by sever ways:

A) Like in modern Czech, the present forms of perfective verbs were used for the future tense. This meant that the future tense of imperfective verbs could be sometimes formed from perfective verbs with similar meaning – sometimes just by adding a prefix (dělaju x udělaju).

B) Although rare, the present forms of imperfective verbs can in some texts be found with the future meaning. Consider the following text:

C) The future tense was also expressed using the present form of an auxiliary or the future form of and an infinitive of the verb. Unlike modern Czech, which uses only the verb, the Old Czech future auxiliary wasn't fixed yet, so verbs like , ,  could be used. The verbs "chtieti" and "jmieti" can be used with imperfective as well as perfective verbs and still mean future:

The auxiliary "býti" is the most important one of them all. The verb "býti" is the only verb that has its own future form. The composed future tense of "býti" is rare: The negative prefix is normally borne by the auxiliary. The contrary is rare: It is also rarely formed with the L-participle instead of the infinitive. It can also be debated whether these rare forms couldn't have been used as a future perfect tense.

Preterite
The preterite was composed from the present forms of and the L-participle. In Proto-Slavic, these forms might have been used to express a situation which was a consequence of a preceding action. The resultative meaning was also in Old Czech so the name "perfect" would probably be better than "preterite". During Old Czech, it gradually became what is the basic past tense in modern Czech. This was supported by the extinction of the aorist and imperfect in the 15th century. The benefit of the preterite compared to the aorist and the imperfect are:
 * it can be formed from perfective as well as imperfective verbs
 * it doesn't have the same forms in the 2nd and 3rd person singular
 * it expressed gender as well as number

Already in the 14th century, the third person started losing the auxiliary – jest/je dělal –> dělal; jsú dělali –> dělali. The auxiliary in the 3rd person became rare in the 16th century. In Old Czech, the negation could be placed on the auxiliary (nenie dělal) which isn't standard in modern Czech.