My own understanding from consulting whatever showed up in web searches is that "kiellettyä" or "sallittua" is "jaollinen" meaning it applies universally, whereas "kielletty" or "sallittu" applies to a specific place, case, or people only. So, yeah, that's how it goes!
Mielipide?
>pahimpina ylityöaikoina on tienannut yli neljää donaa pariin viikkoon
I often encounter situations where I need to decide between e.g. parissa viikossa and pariin viikkoon. What is the grammar rule or logic behind choosing one over the other?
In this example, I suppose both pariin viikkoon and parissa viikossa work, but are there specific grammar rules that dictate which one to use and in what circumstances?
Another example: En ole nähnyt häntä pariin viikkoon / pariksi viikoksi / parissa viikossa.
What distinguishes these two terms? The one found in Wiktionary (sen verran) is the standard version, while the other, which isn't listed there, appears to be more colloquial. Is that accurate?