In the consideration of morpheme sequences it is necessary to include all suprasegmental morphemes such as intonation and stress contours. Thus, the {,} morpheme, which consists of a levelled preceding pitch plus an intermittently present pause, is always present in the equation ''NV, & NV = NVD = NV: We asked him, but he wouldn’t do it' can be replaced by 'We asked him unsuccessfully' or 'We asked him.' In contrast, The {,} morpheme is sometimes present and sometimes absent in the sequence 'NVBN.' (i.e. 'NV, BN. = NVBN.'). The command morpheme {!} is the only contour in whose environment a member of 'V' (e.g. 'hurry') is not replaceable by 'V Vυ' (e.g. 'hurried'): e.g. 'Hurry!' Since 'V' plus this morphemic contour also does not occur with a preceding 'N', we may say that 'V! = NVVυ = NVVυ?' Similarly, intonation contours such as '—ˌˌ— must be noted when they occur. This morpheme, with its rare form ˌˌ—'—, means that the morpheme or sequence bearing the reduced stress /ˌˌ/ refers to, or in some way modifies the meaning of, that bearing the main stress /'/. Many equations which contain this modifier morpheme would not hold if that morpheme were omitted. ''NV ˌˌNV = NVN' is exemplified in the substitution 'I see you’re leaving' for 'I see you'. But ''NV 'NV' would only occur with a sentence contour such as {:} or {?} after each half.
- Harris (1951), Pag. 281