This is the 116th most frequent Czech word.
loni
"Last year."
In this sentence, 'loni' specifies the time when the visit happened, indicating that it occurred in the previous year.
Loni jsme navštívili Český Krumlov.
Last year, we visited Český Krumlov.
In this sentence, 'loni' facilitates specifying the particular year in which the dry summer occurred.
Loni bylo extrémně suché léto.
Last year had an extremely dry summer.
Here, 'loni' is used to reference the point in time that marks the beginning of an event, which is the start of building the house.