Handbook of Finnish, 2nd edition, section 15 Verbs:

Overview of verb inflection

Richness of forms

It has been said that in Finnish a verb can have over 20,000 forms, but this means counting “forms” that are never used in practice, or are actually derived words, or contain word-like suffixes like -han, etc. A more adequate estimate is 260 forms.

Much of verb inflection in Finnish is simple. The only irregular verbs are olla (to be) and the negation verb ei. Otherwise, verb inflection is rule-based. There are complications due to verb stem variation as well as suffix form variation, though.

The most common forms

The frequency of forms varies a lot. In nonfiction prose, the following forms dominate:

Form	Example	Meaning of example
present tense, 3rd person singular	sanoo	[he/she/it] says
present tense, 3rd person plural	sanovat	[they] say
present tense, 4th person	sanotaan	it is said
present tense, negative form	sano^x	say [in negative context]
present tense, 4th person, negative form	sanota^x	is said [in negative context]
past tense, 3rd person singular	sanoi	[he/she/it] said
past tense, 3rd person plural	sanoivat	[they] said
past tense, 4th person	sanottiin	it was said
conditional, 3rd person singular	sanoisi	[he/she/it] would say
conditional, 3rd person plural	sanoisivat	[they] would say
conditional, 4th person	sanottaisiin	it would ne said
present participle, singular	sanonut	that has said
present participle, plural	sanoneet	that have said
active participle	sanova	saying
passive participle	sanottu	said
infinitive	sanoa^x	to say

In instructions, the 2nd person imperative forms are used, e.g. sano, sanokaa. In dialogs, different 1st and 2nd person forms are common, e.g. sanon (I say), sanoit (you said).

Finite forms, participles, and infinitives

The verb forms can be classified into finite forms such as sanoo (says), participles such as sanottu (said), and infinitives such as sanoa (to say).

Finite forms are used as predicates, e.g. Kuka niin sanoo? (Who says so?).

Participles are used in some combined forms, as in English. In such use, the verb olla (to be) acts as the auxiliary verb, e.g. on sanottu (it has been said). Otherwise, participles are used and inflected as adjectives, e.g. sanottu asia (said thing), sanotut asiat (said things), etc.

Infinitives are used in special contexts, often like adverbs. Infinitives have properties of nouns, though with many specialties. For example, the infinitive form sanomalla (by saying) consists of the verb stem sano, the III infinitive suffix ma, and the adessive case suffix lla.

The simple finite forms of a verb are the finite forms formed with inflection only, as opposite to forms using an auxiliary verb, such as olen sanonut (I have said). The simple finite forms are: indicative present tense, indicative past tense, conditional, potential, imperative, each with seven personal forms (six for the imperative). There are also past tense negative forms, which have a special status, as they are only used in conjunction with the negation verb.

Summary of inflected forms of verbs

The following table contains all inflected forms of a verb in standard Finnish, in the following sense:

only simple forms are included, not expressions that use auxiliary verbs, e.g. olen sanonut
infinitives are shown without personal suffixes (-ni, -si etc.), since they are the same as possessive suffixes of nouns; a hyphen “-” at the end of a form indicates that such a suffix is required
participles are shown in nominative singular only, since their other forms belong to inflection of noun-like words rather than verb inflection
reflexive inflection is excluded; it was never a systematic part of the standard language, and it is limited to some forms of old poetry
the general negative form sano^x, as in en sano (I do not say) is not listed separately, since as a form, it is identical with the imperative 2nd person singular

Somewhat illogically, the I infinitive long forms are shown with different personal suffixes, but other infinitives without such a suffix. The reason is that the long form of the I infinitive always appears with a personal suffix.

The verb used in the examples has simple inflection in the sense that the stem sano- does not change at all.

Example	Name of the form	Explanation
sanoa^x	I infinitive, short form	to say
sanoakse-	I infinitive, long form	in order to say
sanoessa	II infinitive, inessive	while saying
sanoen	II infinitive, instructive	(by) saying
sanottaessa	II infinitive, passive, inessive	while being said
sanomassa	III infinitive, inessive	in saying
sanomasta	III infinitive, elative	from saying
sanomaan	III infinitive, illative	to saying
sanomalla	III infinitive, adessive	by saying
sanomatta	III infinitive, abessive	without saying
sanoman	III infinitive, instructive	say
sanottaman	III infinitive, passive, instructive	be said
sanominen	IV infinitive, nominative	say
sanomista	IV infinitive, partitive	say
sanomaisilla-	V infinitive	about to say
sanova	present participle	that says
sanottava	present participle, passive	that is said
sanonut	past participle	that said
sanoma	past participle, passive	that was said
sanottu	past participle, passive, 4th person	that was said
sanon	present tense, 1st person singular	I say
sanot	present tense, 2nd person singular	you say
sanoo	present tense, 3rd person singular	says
sanomme	present tense, 1st person plural	we say
sanotte	present tense, 2nd person plural	you say
sanovat	present tense, 3rd person plural	[they] say
sanotaan	present tense, 4th person	it is said
sanoin	past tense, 1st person singular	I said
sanoit	past tense, 2nd person singular	you said
sanoi	past tense, 3rd person singular	[he/she] said
sanoimme	past tense, 1st person plural	we said
sanoitte	past tense, 2nd person plural	you said
sanoivat	past tense, 3rd person plural	[they] said
sanottiin	past tense, 4th person	it was said
sanonen	potential, 1st person singular	I probably say
sanonet	potential, 2nd person singular	you probably say
sanonee	potential, 3rd person singular	probably says
sanonemme	potential 1st person plural	we probably say
sanonette	potential, 2nd person plural	you probably say
sanonevat	potential, 3rd person plural	[they] probably say
sanottaneen	potential, 4th person	it is probably said
sanoisin	conditional, 1st person singular	I would say
sanoisit	conditional, 2nd person singular	you would say
sanoisi	conditional, 3rd person singular	would say
sanoisimme	conditional 1st person plural	we would say
sanoisitte	conditional, 2nd person plural	you would say
sanoisivat	conditional, 3rd person plural	[they] would say
sanottaisiin	conditional, 4th person	it would be said
sano^x	imperative, 2nd person singular	say
sanokoon	imperative, 3rd person singular	let [him/her] say
sanokaamme	imperative, 1st person plural	let us say
sanokaa	imperative, 2nd person plural	say
sanokoot	imperative, 3rd person plural	let [them] say
sanottakoon	imperative, 4th person	let it be said
sanomaton	negative participle	unsaid; that does/did not say
sanota^x	negative present tense 4th person	it is [not] said
sanone^x	negative potential	probably does [not] say
sanottane^x	negative potential 4th person	it is probably [not] said
sanoisi(^x)	negative conditional	would [not] say
sanottaisi(^x)	negative conditional 4th person	would [not] be said
sanoko	negative imperative	[not] say
sanottako	negative imperative 4th person	let it be [not] said

The web site Verbix.com can be used to generate all forms of a given verb. It includes the forms mentioned above, except for the longer form of the I infinitive, sanoakse-, and the negative imperative form, sanoko. It also includes the following constructs involving an auxiliary verb or the negation verb:

perfect tense forms like olen sanonut etc.
pluperfect tense forms like olin sanonut etc.
conditional mood past tense (“perfect”) formslike olisin sanonut
potential mood past tense (“perfect”) forms like lienen sanonut
imperative mood past tense (“perfect”) forms olkoon sanonut, olkoot sanoneet and olkoon sanottu
negative expressions ei sanota, ei sanottu, ei sanottane, ei sanottaisi, älköön sanottako, älköön olko sanottu

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