This is the 477th most frequent Lithuanian word.
keturi
"Keturi" means "four" in English.
The prefix "ketur" is part of "keturkampis," a compound word describing a shape with four sides (a rectangle).
Viduryje stalo buvo keturkampis padėkliukas.
In the middle of the table, there was a rectangular coaster.
Here, "keturias" is the feminine accusative form of "keturi," describing the duration in weeks.
Marija laimėjo keturias savaites atostogų.
Maria won four weeks of vacation.
The word "keturi" functions as an adjective describing the quantity of the noun "trees" in the masculine plural form.