You're walking on a beach and see a spit. explain how a spit could have formed from a rocky headland

A spit  could form from a rocky headland where prevailing winds would blow at an angle to the rocky headland, gradually depositing sand and shingle at that place.

A spit is a permanent landform resulting from marine deposition and wind deposition. It is usually a long and narrow accumulation of sand or shingle with one joined to the land and the other end projecting at   a narrow angle out into the sea.

Salt marshes sometimes form on the sheltered side of a spit.