Questions & Answers about Meidän talossamme on iso lastenhuone.
Why is the first part of lastenhuone in the genitive case (lasten) instead of the nominative (lapsihuone)?
When a compound noun describes the purpose or the intended users of the second word, the first part takes the genitive case. Because this is a room meant for children, it becomes lastenhuone. If the first part described what the room was made of or its general type, it would use the nominative, just like kivitalo (stone house).
Why do we use the plural genitive lasten instead of the singular genitive lapsen here?
The plural genitive is used because the room is intended for children in general as a group. If it were a room specifically designated for one single child, you might see lapsenhuone, but for general purposes, Finnish logically defaults to the plural modifier.
Why does the sentence start with Meidän talossamme instead of the subject iso lastenhuone?
This is an existential sentence, which is the Finnish equivalent of English 'there is' or 'there are' statements. These sentences usually begin with the location (Meidän talossamme), followed by the verb (on), and end with the new information being introduced (iso lastenhuone).
Since meidän already means 'our', why is the -mme suffix added to talossamme?