Similar to what we described for manual modifications in MORPHOLOGY 2.1.2.1, there is no evidence for a systematic difference in mouth actions between verbs and nouns in NGT. There is, however, a small tendency for nouns to be more frequently accompanied by a mouthing than verbs, and for verbs to be more frequently accompanied by a mouth gesture than nouns. Yet, verbs often also occur with a mouthing or with no mouth action at all, and similarly, nouns are found to be accompanied by a mouth gesture or by no mouth action at all. For example, the verb run_away was encountered with the mouth gesture [puh] but also with the mouthing [weg] ‘away’.
The mouthings that accompany nouns and verbs can be full lexical Dutch words or reduced forms (see also PHONOLOGY 1.5.2). Mouthings accompanying verbs can be inflected for tense and/or person and/or number. Consider again example a above, where the verb eat is accompanied by the mouthing [eet]‘I eat’. In b., the sign eat is also accompanied by a mouthing, but here the signer articulates the noun [eten]‘food’. Thus, although the type of mouth action is not different, the mouthing still differentiates between nouns and verbs.