Questions & Answers about Lámpával megvilágítjuk a fát.
Because -val / -vel is the Hungarian suffix meaning with.
- lámpa = lamp
- lámpával = with a lamp
This suffix is often called the instrumental-comitative ending. It can mean:
- using something as a tool: késsel = with a knife
- being together with someone/something: a barátommal = with my friend
In this sentence, it shows the instrument used to illuminate the tree.
Because many Hungarian nouns ending in -a or -e change that final vowel to a long vowel before many suffixes.
So:
- lámpa → lámpá-
- then add -val
- result: lámpával
The same thing happens in many other words:
- szoba → szobában
- mese → mesét
So the long á in lámpával is a normal stem change.