Signature communities are sociolinguistically very different from spoken language communities, as the number of indigenous signatories is very low in most communities and is linked to the interruption of transmission for generations (for example. B Schembri – Johnston 2007). The result is a very apparent and particular variation in all aspects of language use, including morphology. As relatively young languages (Newport – Supalla 2000), many of the morphosyttics in sign languages do not appear highly grammatically and are therefore often optional. For example, large-scale quantitative studies to indicate verbs in BSL and Auslan data show that the use of spatial changes in such signs to reflect the position of real or imaginary references occurs in 60-70% of all tokens (from Beuzeville et al. 2009; Fenlon et al. 2018). As mentioned above, such peculiarities are to be expected under a building grammar account, as different individuals who indicate verb structures have different characteristics. In (13), we see the next approximation in sign language, which gives verbs to Steeles (1978) definition of the agreement, adding some formal features of this shaping of the BSL/Auslan CHILD logo (i.e. the fact that it is produced here at a place on the left side of the signatory) with formal ownership of the corresponding TELL→ badge.
The next step towards an agreement system is seen when the verb is no longer limited to the Z axis. Some signatories have established forms in which the initial position of the sign is on the body of the signatory and whose final point is directed towards a spatial place associated with the object`s argument. However, it is essential that the position associated with the argument is not on the Z axis, but on the right or left of the signatory (see Figure 2). In other words, the “loose” end of the verb can be addressed to any position related to an argument at the signature level. These forms can be considered as marked verbs for an agreement with a single argument.4 The reanalysis of the final position of the verb as Morpheme marking agreement with an argument is over. This morphum is not limited to a certain value (a point in space on the Z axis), but may accept any value of an R locus associated with the verb argument.