As has been already explained in the Accidence the greater number of these words in Finnish are declinable substantives, and take the various cases under just the same rules as an ordinary noun. With the exception of a certain number of petrified and isolated forms, they may be compared to the word midst in English. We say he came from the midst, went into the midst, or stood in the midst. In the language of Finnish grammarians such forms would be considered as adverbs. Whereas in such expressions as in the midst, or from the midst of the crowd, they would be called postpositions or prepositions. This practice of declining adverbs and postpositions is, however, carried to lengths for which no analogy can be found in English. Thus myöhä, is late (an adjective), but to come late is rendered by tulla myöhään; on account of the idea of motion in the verb. To watch late into the night is valvoa myöhälle yötä, and such an expression as later on (of a date) is rendered by the essive myöhempänä.
Most, but not all, postpositions, are capable of taking the pronominal affixes, with or without a genitive of the personal pronoun before them.
The subjoined list of prepositions and postpositions gives all the words considered as falling under these categories by ordinary grammars. As a matter of fact, it might very well be either enlarged or curtailed, which last would be better, as some of the words are substantives in ordinary use. But I have thought it better to adhere to the conventional list.
I. Postpositions and Prepositions used in only one case.
(1) Ennen (instrumental of ensi). Preposition followed by partitive. Before. Ennen Kristuksen syntymää, before the birth of Christ. Ennen aikojansa, before one’s time; too soon. Ennen tuloani, before I came.
(2) Halki, across. Preposition followed by genitive. Halki metsän, through the wood. Lenti kokko halki taivon. (Kal. ii. 265).
(3) Ilman (instrumental of ilma), without, preposition with partitive. Ilman apua, without help. Ilman rahaa, without money. Ilman sitä, besides. Also used with the abessive. Ilman muiden avutta, without the help of others. Hän otti rahat vastaan ilman lukematta, he received the money without counting it. Ilman maan alistamatta, Ilman kasken kaatamatta (Kal. ii. 254).
(4) Kanssa, with. Postposition with the genitive. Pojan kanssa, with the boy. Isänsä kanssa, with his father. Kanssa takes the pronominal suffixes. Minun kanssani, sinun kansassi, hänen kanssansa, etc. Hän kulki kanssani koko matkan, he went all the way with me. Puhuiko hän kanssasi? did he speak to you?
(5) Kautta (partitive of kausi). Postposition after the genitive, through, or by the help of; like kanssa it takes the pronominal suffixes. Minun kauttani, by my help. Hän on tunnetu isänsä kautta, he is known on account of his father. Also used as a preposition in the sense of all over. Huhu leviää kautta kaiken kaupungin, the rumour spreading over the whole city. Kävelimme kylien kautta, we went through the villages.
(6) Paitsi, besides. Preposition with the partitive. Paitsi sinua ei ole minulla yhtään ystävää, I have no friend but you. Paitsi sitä, besides this. Paitsi veljensä apua olisi hän joutunut hukkaan, he would have been ruined without his brother’s help.