Questions & Answers about Hän lähti toimistosta tervehtimättä minua.
How do we build the word tervehtimättä?
This is the third infinitive abessive form, which is used to say you do something "without" doing another action. To build it, find the strong stem of the verb tervehtiä (to greet) by removing the infinitive ending, which gives you tervehti-. Then, just add the abessive ending -mättä.
Why does the ending use -mättä instead of -matta?
This is due to vowel harmony. The verb tervehtiä only contains the vowels e, i, and ä. Because there are no back vowels (a, o, u) in the word, the ending must use the front vowel ä.
Why is "me" in the partitive case (minua) here?
The verb tervehtiä (to greet) is a partitive verb, meaning its object must always be in the partitive case. Even when it is changed into the -mättä form, it still acts like a verb and forces its object (minä) into the partitive (minua).
Why does toimisto have the -sta ending here?
The verb lähteä (to leave) requires a "from" case to show where someone is leaving from. Because an office (toimisto) is an enclosed space, you use the elative case -sta (out of) rather than the ablative -lta (off of).