The most common conjunctions in Finnish are eli (or, in other words), että (that), ja (and), joko … tai (either … or), jos (if), joskin (although), jotta (in order to), koska (because), kuin (than; as), kun (when), mikäli (if), mutta (but), sekä (and), sekä … että (both … and), sillä (since, because), tai (or, alternatively), vaan (but), vai (or), vaikka (even though; in spite of).
Many conjunctions form contractions with the negation verb en : et : ei : emme : ette : eivät. For example, instead of että ei it is normal to write and say ettei. This is described in more detain in section Negation verb combined with other words.
The words ellei and jollei are effectively contractions of jos (if) with the negation verb in modern language, though not historically. They both mean “unless” or “if not”. The ei part in them is inflected, e.g. ellen, ellet, so that e.g. “If we do not accept this” is Ellemme hyväksy tätä or Jollemme hyväksy tätä, though Jos emme hyväksy tätä is possible. too.
The words jos and mikäli are normally synonyms. In old usage, mikäli means in principle “to the extent/amount that…”. In practice, it is mostly used simply to mean “if”, perhaps for emphasis (since it is longer than jos). The word pair sikäli mikäli is also used to mean “if”, but it should be regarded as informal style and used to emphasize conditionality.
In English, the word “if” is also used for subordinate questions, as in “He asked if the train had arrived”. ) In Finnish, the kO suffix is used instead, e.g. Hän kysyi, oliko juna tullut. The suffix is appended to the key word of the question. Although the word josko (or just jos) is often used instead, e.g. Hän kysyi, josko juna oli tullut, such usage is substandard.
The words ja and sekä have the same meaning, but ja is normal, whereas sekä is typically used as a “higher level” conjunction: A ja B sekä C ja D means that A and B are grouped together, and so are C and D. It is also used otherwise to avoid having the word ja repeated too often. However, sekä is often used instead of ja for no apparent reason, as a matter of personal style.
The word ynnä is used the same way as sekä, but it is rare. Except for some phrases like ynnä muuta (and so on), usually abbreviated ym., it is old-fashioned style.
The difference between mutta and vaan is contextual: vaan is normally used after a negative statement, e.g. Hän ei mennyt Turkuun, vaan Poriin “He did not travel to Turku, but to Pori”. Here, and usually, a vaan statement complements a preceding negative statement with information on what actually happens or with a suggestion of what should be done. Example of the latter: Älä lähde vielä, vaan istu hetki (Don’t leave yet but sit here for a moment).
In contexts like “I have not eaten anything but an apple”, “but” corresponds to kuin in Finnish: En ole syönyt muuta kuin omenan.
The usual expression for “both … and” is sekä … että, e.g. sekä työssä että kotona (both at work and at home).
As an alternative to sekä … että, the construct niin … kuin can be used. The latter part of the expression normally has the kin suffix, so that the construct is really niin … kuin …kin. For example, instead of sekä kissat että koirat (both cats and dogs), we can say niin kissat kuin koiratkin, which might be translated as “cats as well as dogs”, but there is hardly much difference in tone. It is nowadays common to omit the kin suffix here, e.g. niin kissat kuin koirat, especially if the expression as a whole is long.
The construct paitsi … myös corresponds to “both … and”, but with emphasis on the second part. E.g. Tätä voi käyttää paitsi työssä myös kotona more or less takes the työssä part for granted, so the sentence could be translated “This can be used not only at home but also at work.”
The connective suffix kä is logically a conjunction meaning “and”. However, it is not a separate word but appended to a form of the negation verb, e.g. eikä (and not). It is normally used instead of ja or sekä when these would be followed by the negation verb. For example, instead of En tiedä ja en halua tietää we normally say En tiedä enkä halua tietää (I do not know and I do not want to know).
As the list above shows, there are three conjunctions in Finnish corresponding to English “or”:
These distinctions often make sentences less ambiguous and easier to interpreter. Consider a question like “Did you meet Peter or Anna?” There are two possible interpretations, corresponding to the Finnish questions Tapasitko Peterin tai Annan? (expecting a yes or no answer) and Tapasitko Peterin vai Annan? (implying that one of them was met and expecting an answer that tells which one was met).
A word of warning about eli: in spoken language, it is nowadays often used at the start of a sentence with no real meaning, just as an opening word (a bit like “well” in English). This can be rather confusing if you expect it to appear in the literary meaning.
The conjunction tai (or) is normally “inclusive or”. The question Onko sinulla kissa tai koira (Do you have a cat or a dog) includes the possibility of having both a cat and a dog. However, it is not uncommon to claim theoretically that tai is or should be exclusive and to use ja/tai for an inclusive or, imitating the English expression “and/or”. Such usage has been regarded as substandard by language authorities, but this has changed to some extent.
In some contexts, tai is usually understood as exclusive, though somewhat debatably. For example, the statement Voit saada kahvin tai jäätelöä (You can have coffee or icecream) might be understood in two ways. The combined conjunction joko … tai is normally exclusive, corresponding to English “either … or”, so it can be used for clarity: Voit saada joko kahvin tai jäätelöä excludes the possibility of having both.
It is normal to ask Haluatko kahvia tai teetä? (Do you want coffee or tea?) Even though one is in practice expected to select either coffee or tea, we do not use vai here, since it would be somewhat impolite or pushy. It would take it for granted that either coffee or tea is to be selected.
In standard Finnish, että is used to start a subordinate clause much like “that” is used in English, e.g. Sanoin, että tulen huomenna (I said that I will come tomorrow). Unlike the English “that”, että cannot be just omitted in sentences like that. On the other hand, a statement starting with että can often be replaced by a clause equivalent, but this means a major change in the structure, e.g. Sanoin tulevani huomenna.
The word että also appears as part of some two-word conjunctions, e.g. siten, että (so that).
The conjunction jotta is used in standard Finnish in a rather specific meaning. Basically it indicates purpose, corresponding to “in order to” or “for the purpose of”, e.g. Aloin juosta, jotta ehtisin junaan (I started running in order to catch the train). Such a subclause can usually be replaced by an intentional clause equivalent, e.g. Aloin juosta ehtiäkseni junaan.
The word jotta is also used to indicate consequence, especially in some forms of spoken Finnish and in some writing styles. Example: Juoksin jotta sydän pamppaili (I ran so that it made my heart go pitapat). It is debatable whether such usage is standard Finnish. In any case, using niin, että instead of jotta would be safer here.
I dialects, että and jotta are often used in manners that deviate from standard Finnish. In particular, it is common in many areas to use jotta generally instead of että, e.g. Sanoin, jotta tulen huomenna.
Except for some special conditions, the conjunctions että and jotta are preceded by a comma. (This does not apply to the sekä… että construct.)
The conjunction kun primarily expresses temporal relations, similarly to “when” in English, whereas kuin expresses comparison of some kind, often corresponding to “than” or “as” in English. In common spoken Finnish, this distinction is usually not made; kun or just kux is used for both. The rules of standard Finnish are somewhat artificial in this respect, and there are situations where it is not clear whether temporal relation or comparison is involved. This explains why native speakers often have problems in using kun and kuin correctly in writing.
The word kuin corresponds to “as” when expressing similarity and to “than” when used with a comparative form. Examples:
The word kuin is often used together with another word or other words before it so that the two form functionally a single conjunction (but still written as a two words in standard spelling):
Somewhat illogically, ennen kuin is interpreted as involving comparison, so it has kuin and not kun, but sitten kun (after) is interpreted as temporal, so it has kun.
The distinction between kuin and kun is somewhat artificial. Oldest written Finnish uses kuin for both purposes, whereas spoken language has done the same with kun. In the 19th century, the current division was established, thought some changes have been made to the rules.
It is not always clear whether comparison or time is involved, especially when combined conjunctions are used. Even native speakers often need to check language guides in such issues. The most common combined conjunctions and contexts are the following:
Some words used as conjunctions have completely different use, too. In addition to the mixed use of että and jotta described above, the following words can be ambiguous: