Verb aspects are not a grammatical feature in Finnish verb inflection, but derived verbs are sometimes categorized under groups occasionally called verb aspects by Finnish grammars.
Frequentative verbs generally express repetitive action, but may also represent leisurely and/or prolonged activity, or activity that is not done in a particularly determined attempt to reach a goal. The frequentative class of derivatives is highly productive.
The most common frequentative endings are -ella and -illa, but several further frequentative endings have been fossilized into longer suffixes, like -nnella, -skella and -skennella. The continuative suffixes -ia, -oa, and furthermore -htia, -ksia, besides deriving continuative verbs, may also derive frequentative verbs as well.
Frequentative verbs tend to be atelic quite often.
Continuative verbs express an action that lasts for an extended period of time (note that this differs somewhat from the common English definition of the continuative aspect, representing actions that are still ongoing). The original continuative suffix is -ia, and further derivatives of it include -oa, -htia and -ksia. In some cases the suffixes -oida, -ita and -ajaa may also derive continuative verbs.
Momentane verbs express a sudden, brief action. The primary momentane suffixes are -ahtaa and -aista, and to a lesser extent also -altaa. Momentane verbs, especially -ahtaa verbs, may also have a semelfactive meaning (i.e. expressing that an action occurs only once, is of an instantaneous nature and is not done in attempt to reach a goal).
Causative verbs express an action that is caused by the subject. The primary causative suffixes are -taa and -ttaa. Others include -oida, -ta, -ittaa, -istaa, -oittaa, -uttaa and -uuttaa.
Curative verbs are a subclass of causative verbs. They express an action in which the subject (agent) makes the object (patient) perform an action. The primary curative suffix is -ttaa. Others include -uttaa and -uuttaa.
Emotive (or emotional-causative) verbs express an action that causes the patient to feel an emotion, often implying a source for the emotion. Emotive verbs are, without exception, monopersonal, since they are semantically a subclass of causatives where the patient feeling the emotion is grammatically an object, and the grammatical subject (agent) is omitted. Practically all emotive verbs are derived with -ttaa.
Factitive (or factive) verbs express an action where the subject (agent) makes the object (patient) adopt a certain end state or quality. The primary factitive suffix is -taa. Others include -ntaa, -istaa, -ta, -ittaa and -oittaa.
Factitive verbs are generally only telic if there is a definite end goal or state that something reaches. With most adjectives, the resulting verb is usually atelic. For example, jäykistää (“to stiffen”) (from jäykkä (“stiff”)) can be used telically, since the definite end state is that something is stiff. By comparison, syventää (“to deepen”) (from syvä (“deep”)) is rarely used telically, since things are rarely objectively "deep".
Automative (sometimes passive or anticausative) verbs express an action that is done upon the subject (patient) or that affects its subject. The primary passive suffix is -ua. Others include -tua, -htua, -stua, -pua, -utua and -Vntua.
Reflexive verbs express an action done by the subject upon itself or themselves. The primary reflexive suffix is -utua.
Translative (inchoative) verbs express an action where the subject (patient) becomes something or adopts a quality of some kind. The primary translative suffix is -ua. Others include -tua, -Vntua, -utua, -stua, -eta, -ta and -ota.
Sensive verbs express an action in which the subject feels an object to be a certain way. The primary sensive suffixes are -ksia and -ksua.
Captative verbs express a hunting or capturing action. The primary captative suffixes are -staa and -taa.