The essive or similaris case carries the meaning of a temporary state of being, often equivalent to the English "as a...".

In the Finnish language, this case is marked by adding "-na/-nä" to the genitive stem of the noun, but with strong consonant gradation. Example: "lapsi" -> "child", "lapsena" -> "as a child", "when (I) was a child".

In Finnish, it is also used for specifying times, days and dates when something happens. For example: "maanantaina" -> "on Monday", "kuudentena joulukuuta" -> "on the 6th of December". Some expressions use the essive in the ancient locative meaning, e.g. "at home" is "kotona". Observe the similarity to English "at home/in my home":

• Luen lehtiä kotona. "I read newspapers at home." If you use the inessive, kodissani, you contrast to reading them in the garage (a physical location) instead.
• Kodissani tehdään remonttia. "In my home, a renovation is underway."