Signs may either be articulated with one hand as in a. or with two hands as in b.
a. beautiful
b. grammar
Two-handed signs are subject to specific phonological constraints. Within symmetrical signs, both hands are specified for the same handshape and perform the same movement (simultaneous or alternating). The orientation must be symmetrical or identical (rule of symmetry). If both hands take on different handshapes in a lexical sign, the non-dominant hand is the location for the articulation of the sign and is specified for one of the unmarked basic handshapes (rule of dominance). Such signs are called asymmetrical signs. In some asymmetrical signs in DGS, the non-dominant hand is specified for a marked handshape but only if it has the same handshape as the dominant hand.
One-handedness and two-handedness do not function as a distinctive feature in DGS. But phonetic variation is possible. For example, for the purpose of emphasis a one-handed sign may be articulated with two hands. This can be observed with the sign can in DGS, for instance.
can (one-handed) – can (two-handed)