This is not something we have to study or learn separately for every word. If you know Finnish, understanding or knowing all these words should come natural.
The Finnish language doesn't have prepositions. Instead we ad suffixes to the end of the words. For example "To school" in Finnish is "kouluun"
The thing is that you can combine these suffixes, basically putting multiple suffixes to the end of the word and have it make sense.
For example: when forming a question, you use the "-ko/-kö" suffix. so "To school?" (in the context would be Koulu(school)-un(to)-ko(question)?, so it would be "kouluunko?"
Okay we know how to write "to school?" in Finnish. Lets add another suffix:
the suffix "-han" is used when you are wondering or questioning something.
So "kouluunkohan" (koulu-un-ko-han) means "I wonder (if) ... to school?". The word still makes sense, and is grammatically correct, but truthfully speaking it is starting to become a bit ridiculous and no one would probably use it in a conversation.
I think my favorite example of this is "Lampsisinkohan". The word Lampsia means "to walk lazily". The "-sin" suffix means "I would". The "-ko" suffix was the question one, and "-han" was the pondering/questioning/wondering one.
So "Lampsi-sin-ko-han" in English means "I wonder if I should walk lazily?"
"lampsisinkohan kauppaan?" "I wonder if I should walk lazily to the store".
There are, however, a couple things that are legit weird.
For example:
The word for "(to) sit" is "istua". To say "I sit" you replace the last letter with the suffix "-n", so it's "istun". The word "(to) step" in Finnish is "astua". Again to say "I step", you replace the last letter with the "-n" suffix; "astun". In Finnish the "-n" suffix relates to "self" etc. so if there's word ending with "-un" or "-n" it's probably relating to the speaker.
Simple, right? Wrong.
How about the word "to run". That's "juosta".
So to say "I run" you would just have to replace the last letter with a "-n", right? Nope, "juostn" is wrong. Triple consonants are rarely (if at all) a thing in Finnish.
Well maybe you just add the suffix to the end of the word because it doesn't have a double vowel like "istua", right? "Juostan"? Nope that's wrong also.
Well maybe the suffix has to replace the last letter of the last vowel pair in the word, so maybe it's "Juon"? Nope that's "I drink", coincidentally.
The way to write "I run" in Finnish is "Juoksen". Why the -ksen suffix? why put it in the middle of the word? Why not Juostaksen? **** if I know... I just know that that's how it is. (coincidentally "juostakseni" means "for me to run" or "...So I could run.." etc.) It's really weird.
"to walk" is "kävellä"
"I walk" is "kävelen". not "kävellän" or "kävelln" or "käven" or "käveksen".
Again, way different and makes no sense.
These are the things that foreign speakers have the most problems with I think. you just kinda gotta know what suffixes go where.
even the kid's education these days are trying to brain wash children to think that eating the flesh of another is ok, when their is clearly nothing more wrong than making your stomach into a graveyard.