In this article, you can find examples of verbs that have an exceptional imperfect conjugation (e.g. lentää → lensi). The focus on this article is specifically on verbtype 1 verbs that end in -LTAA, -RTAA, -NTAA and –vvTAA. These verbs will get -si- in their imperfect conjugation (e.g. lentää → minä lensin, hän lensi, me lensimme).

In the tables below, I’m conjugating each verb in the third person singular. However, the -si- will appear in all the persons.

For the verb rakentaa, for example,

• minä rakensin – I built
• sinä rakensit – you (singular) built
• hän rakensi – he/she/it built
• me rakensimme – we built
• te rakensitte – you (plural) built
• he rakensivat – they built

This article is based on a comment by Rasikko on the article about the imperfect tense.

Why does lentää become lensi?

This topic will be discussed more thoroughly in another article. If you’re just trying to learn to speak Finnish, the WHY isn’t all that important. Nevertheless, I know students like to know the reason behind unusual forms.

For this type of verbs the why is buried deep in the past of the Finnish language. We have to go back more that a thousand years BC. We don’t have any sources that show us what Finnish was like back then, but linguists have reconstructed as much as they can based on the differences and similarities between Finnish and the languages closely related to it.

The -si- in rakensi, tiesi and ymmärsi most probably is the result of a “ti ~ si change”. There was a period in the history of the Finnish language where people started replacing -ti- with -si- in certain types of words. That seems to fit together nicely with what you’d expect the imperfect of these types of verbs to be:

• rakentaa: hän rakenti → rakensi
• tietää: hän tieti → tiesi
• ymmärtää: hän ymmärti → ymmärsi

There is more to it than just that, but that’s the topic of a separate article!

Lentää lensi – Imperfect of -NTAA verbs

Verbs ending in -NTAA will have the ntaa/ntää become -nsi (e.g. lentää → lensi). The only exception I’ve come across is kyntää “to plow”, which becomes hän kynti rather than hän kynsi to avoid confusion with the noun kynsi “nail”.

There are a couple of verbs of two syllables that end in -NTAA, but don’t belong to this group. These verbs have a…a in the present tense, which will become -oi- in the past tense. I call this type of verbs a…a → oi verbs: verbs such as antaa (hän antoi) and kantaa (hän kantoi).

Marked in green, as always, are the most basic of the verbs, aka the ones you should start with if you’re a beginner or intermediate student.

Kieltää kielsi – Imperfect of -LTAA verbs

Nearly always, verbs ending in -LTAA will get -lsi- in the imperfect. The “nearly” is important for the verb yltää “to reach” for example. For the hän and he forms, there are two possible imperfect variants. For hän, we can have ylti and ylsi, and for he, we can have yltivät and ylsivät. For the weak forms of the verb, -si- is the most common (minä ylsin, sinä ylsit, me ylsimme, te ylsitte). This is probably due to an effort to avoid the minä yllin, sinä yllit type of weak forms.

Ymmärtää Ymmärsi – Imperfect of -RTAA verbs

This group of verbs is fairly small: -RTAA turns into -rsi.

Some exceptions do exist:

• sortaa “to oppress” will usually become minä sorrin, sinä sorrit, hän sorti. The forms minä sorsin, sinä sorsit, hän sorsi are also possible, but likely avoided to distance the word from the plural partitive sorsia “ducks” word.
• kaartaa “to go around, curve” will usually become minä kaarsin, sinä kaarsit, hän kaarsi. However, equally correct are minä kaarroin, sinä kaarroit, hän kaartoi (as is common for a…a → oi verbs).
• saartaa “to surround, encircle” has the opposite tendency. It will usually become minä saarroin, sinä saarroit, hän saartoi. Equally correct, however, are the forms minä saarsin, sinä saarsit, hän saarsi.

Tietää Tiesi – Imperfect of –vvTAA verbs

In the first table below, you can find the clear cases, where –vvTAA (vowel vowel TAA) turns into –vvsi. Unfortunately there are many verbs that aren’t as clear, which you can find evidence of in the table lower down.

Exception tendencies

1. When a verb looks like SvvTAA (see #1), you can see a strong tendency away from -si. The -s- at the beginning of the words seems to try to push the norm towards a different ending. These verbs have consonant gradation: minä syydin, sinä syydit, hän syytii, me syydimme, te syyditte, he syytivät.
2. For some words, the -si variant would have caused a clash with another word that sounds similar (#2). Hän jouti is preferable because jousi means “a bow”, hän vuoti because vuosi is “year” and hän nouti because nousi is “he got up”.
3. If you google “hoisi“, you can find several forum posts where confused Finns ask for clarification of whether this form is correct. In general hoitaa becomes hoiti. Hoisi is just used in the spoken language of some Finns.
4. For verbs like the ones below at #4, there are two options and both are fine to use. I haven’t been able to come up with any reason why these verbs have two possible imperfect conjugations.

Read more elsewhere

• Kielikello: Miksi ylti ja ylsi mutta ei tieti ja tiesi
• Kielitoimisto: Taivutustyyppejä: verbit kiisi ja kiiti, kaarsi ja kaartoi
• Kielikello: Jouksija kiisi voittoon – vai kiitkö hän?

That’s it for verbs like lentää → lensi and ymmärtää → ymmärsin! I hope this article helped!

Related posts:

Auttaa Auttoi – Verbtype 1 Imperfect Tense The Imperfect Tense – Past Tense – Imperfekti Imperfect Perfect Plusquamperfect – When to Use? The Imperfect and Perfect Tense: Examples