What it does
Mercha Kefulah is the doubled form of Mercha. Like its singular cousin, it's a conjunctive that leads forward, but the doubled visual signals an unusual or emphatic moment in the text. It is extremely rare.
Where it appears
Only five times in the entire Torah. When it appears, it carries a special melodic flourish that makes it stand out audibly even to listeners not following the marks on the page.
How to remember it
Kefulah means "doubled." The mark is two adjacent Mercha strokes below the letter, doubling the single curved slash. The melody similarly doubles, adding extra ornamentation.
Example from the Torah
Bereishis 27:25
Each of the five appearances of Mercha Kefulah is memorized by experienced baalei kriah. The rarity is part of the teaching: it forces close attention to the text whenever it shows up.
Hear the melody
A synthesized rendering of the melodic shape, not a vocal recording. For a baal koreh's voice on a full aliyah, PocketTorah is a great free resource.
Hand signal (simanim)
Often confused with
Mercha is one stroke; Mercha Kefulah is two adjacent strokes. Functionally similar but Kefulah is much rarer.