Finnish lacks a verb corresponding to “to have” (or “to have got”) in English. Sometimes the verb omata : omaan (to possess) is used, but it is generally regarded as substandard style in most situations. The verb omistaa clearly indicates (legal) ownership and is thus unsuitable for most contexts where we use “to have” in English.
The normal way to express a thing like “I have a dog” in Finnish is to use a construct like minulla on koira. Here minulla is the adessive form of the pronoun minä (I), on is a form of olla (to be), and the noun koira is in the nominative. Literally, the sentence could be explained in English as “at me [there] is [a] dog”.
The predicate is always in 3rd person singular, i.e. on, oli, olisi, lienee, on ollut, oli ollut, olisi ollut, or lienee ollut, depending on tense and mood. Example: Heillä on uudet vaatteet (They have new clothes).
The noun Y in an expression like X:llä on Y is regarded as the subject in most grammars. However, if a personal pronoun appears instead of a noun, it is in the accusative form: Minulla on sinut. This suggests an interpretation where the clause has no subject, just a predicate, an object, and at least one adverbial. Thus, in this special expression type, the verb olla does not have a predicative but an object.
The case of the noun Y in X:llä on Y is either the partitive or the nominative, except that instead of the nominative, the accusative is used for those pronouns that have it. The partitive is used
Otherwise, the nominative (or the accusative) is used, e.g.
The nominative is also used in some negative expressions. In the sentence Minulla ei ole yhtä hyvä auto kuin sinulla (I do not have as good a car as you have), the nominative is used because the negation applies to an attribute of the noun and that attribute expresses comparison. In the sentence Minulla ei ole lupa puhua siitä (I am not permitted to speak about it), the nominative lupa is used, because it is part of a phrase on lupa (it is permitted).
This construct is also used in contexts where English has rather different structure, e.g. minulla on nälkä (I am hungry; literally: I have hunger). Alternatively, we can say olen nälkäinen, which structurally corresponds to “I am hungry”, but this is not common, and it would change the style somewhat. In addition to nälkä (hunger), this structure type is used for jano (thirst), päänsärky (headache), etc. Example: Onko sinulla jano? (Are you thirsty?).
We also say Minulla on hyvä olo (I’m well; literally: I have good being).
In expressions about possession, word order can be more significant than in Finnish in general, changing the meaning completely. The sentence Minulla on koira corresponds to “I have a dog”, indicating ownership or at least more or less permanent relation, even though the word form minulla as such means roughly “in my possession” or “on me”. But the sentence Koira on minulla refers to some dog, known from the context, and states that he is now in my possession, under my control—for example, when a dog had been lost and has now been found, so that we would say “I’ve got the dog” in English.
Some confusion is possible because adessive forms like minulla may also denote other things. For example, in the statement pihalla on auto the adessive pihalla of piha (yard) simply denotes location, and the statement says that there is a car on the yard. But a statement like Pihalla on auto could also mean “Piha has a car”, where Piha is a person’s name!
When referring to parts or properties of inanimate things, the inessive is normally used, e.g. autossa on vain kaksi ovea (the car has only two doors). It may also be used when the possessor is a living thing. For example, Koiralla on kirppuja and Koirassa on kirppuja both mean “The dog has fleas”, but the latter has a somewhat different tone: there are fleas in the dog.
Finnish uses locational cases systematically to express gaining possession, possessing, and losing possession. Outer cases are used. Examples: Minulle ostettiin polkupyörä (A bike was bought to me), Minulla on polkupyörä (I have a bike), Minulta varastettiin polkupyörä (A bike was stolen from me).
Lack of possession is expressed using the ablative in some contexts, e.g. Minulta puuttuu polkupyörä (I lack a bike).