Many adverbs are formed from adjectives by replacing the ending with -i.
labs
labi
good — well
ātrs
ātri
fast — quickly
skaists
skaisti
beautiful — beautifully
slikts
slikti
bad — badly
Viņš runā latviski.
He speaks Latvian (lit. ‘in Latvian’).
Many adverbs are formed from adjectives by replacing the ending with -i.