The back of greenish warblers is greyish-green and the belly is pale white. There is a narrow and quite short stripe on the wings. They have a fairly distinct light-coloured supercilium on top of the eye, and there is a dark eye strip at eye level. Their beak is dark, relatively slender, and sharp. The male and female bird look alike. They live on slopes and dales, where there are high broad-leaved trees. They mostly live in the crowns of high broad-leaved trees. Their song is hurried and rhythmic, similar to that of wrens. In Estonia, they are sporadically spread hatchers. They build their nest in hollows in the ground, under bigger rocks, between rocks and tufts, and other similar hidden places. Only the female bird builds the nest. They use dry thin reed, horsehair, and moss as nest material.