In this unit, we have taken apart the phonological elements that contribute to making a sign and examined each of them in detail. Now it is time to put them back together again and to look at the system from a somewhat broader perspective. First, we attempt to draw together areas of consensus among researchers with regard to the phonology of sign language. Still unresolved issues emerge at every turn, which point the way to future research.

From this broader perspective, the overall architecture of the phonological component comes into view, and with it the relation of that component to the rest of the grammar. We will review some of the differences between the phonological patterning of words in the lexicon and phonological patterning at the level of phrases and sentences. This bifurcation is found in spoken languages as well, and may be considered universal.

At the same time, sign languages have a third level of structure to draw on, one that we will call non-lexical, which is particular to the modality. At this level, the dividing lines between phoneme and morpheme on the one hand, and form and meaning on the other, are blurred, as are certain constraints on structure. But the contrast between lexical and non-lexical does not erode the imprint of linguistic structure on sign language; on the contrary, it places it in high relief.

The last topic is that of the differences between the two modalities.