Cyrillic Capital Letter Ef

It makes the f sound. The letter is called ef; its older name is fert. Ф is used in Ukrainian and other Cyrillic alphabets as well as Russian. In Old Church Slavonic, an early written Slavic language used for Christian texts, it appeared chiefly in borrowed words because /f/ was not a native sound.

Cyrillic developed in the First Bulgarian Empire in the late 9th or early 10th century, probably around Preslav. Its letter shapes drew on Greek writing and were adapted for Slavic Christian texts and administration.

Why does Ф look like Greek Φ?

Greek phi provided its visual model. Early Cyrillic drew on Greek uncial, a style of rounded capital lettering. Glagolitic was an earlier Slavic script and shared some sound values with Cyrillic, but it was not the visual model for Ф.

The letters are historically connected but remain distinct characters. Depending on the font, Ф and Φ may have different loop widths or stem heights, or look nearly identical.