Imperfect Tense, Middle Voice

What used to be?
What was going on?
 

Compare:

Present Tense
Primary Endings		   Imperfect Tense
Secondary Endings
I   am fighting     μάχ ομαι I   was fighting     ἐ μαχ όμην
you   are fighting  μάχ ει / ῃ you   were fighting  ἐ μάχ ου
he/she/it   is fighting  μάχ εται he/she/it   was fighting  ἐ μάχ ετο
we   are fighting  μαχ όμεθα we   were fighting  ἐ μαχ όμεθα
you   are fighting  μάχ εσθε you   were fighting  ἐ μάχ εσθε
they   are fighting  μάχ ονται they   were fighting  ἐ μάχ οντο
 
Note: 1. The 'you are fighting' should have been: μάχεσαι, but:
Note: 1. the σ was dropped and since ε + αι becomes ει or ῃ
Note: 1. 'You my friend fight' is μάχει or μάχῃ
Note: 2. The 'you were fighting' should have been: ἐμάχεσο, but:
Note: 2. The σ was dropped and since ε + ο becomes ου
Note: 2. 'You my friend used to fight' is ἐμάχου .

So: 'Were you travelling?' ἐπορεύou ;  
So: 'What did you want?' τί ἐβούλou ;