There are 15 cases in Finnish: a group of common cases, a group of six local or locative cases, and a group of relatively uncommon cases.
The most important case for Finnish-language learner is the nominative (nominatiivi). It is the “dictionary” case; a word in this form can be found in the dictionary. If a word is in another case, you need to change it to its singular nominative form to be able to look it up in a paper dictionary. Online dictionaries offer suggestions that make looking up words in a dictionary easier.
Finnish cases coincide with some English prepositions, such as inside, on, and from. In Finnish, cases have case endings (suffixes). As it sounds, you attach cases to the ends of words.
In English, it is common to see more than one preposition in a row. Sometimes, this is due to the use of phrasal verbs; phrasal verbs are outside the scope of this documentation. For example, “Go in on it”. On the contrary in Finnish, you can only use one case at a time for any given word; you cannot attach one case ending after another.
In addition to case endings, there are different types of suffixes that can be added to a word, such as the plural marker i, the possessive suffixes, the suffix -kin (too), the question marker -ko / -kö, and the suffix that provides emphasis -han / -hän.