Conditional clauses express a condition, and the consequence of it is expressed in the main clause. An example is 'If it keeps on snowing, I’ll take the bus'. The first part, 'if it keeps on snowing', is the conditional clause. Only little information was available on this type of subordinate clause in NGT, so many questions regarding its realization were still open: which signs may function as manual markers? Are there specific non-manual markers (such as raised eyebrows)? And is the main clause always preceded by the conditional clause?
In this study, the Corpus NGT was used to analyze naturalistic data. In total, 407 sentences have been analyzed, of which 357 included a manual marker, and 50 only had non-manual marking. It turns out that there are at least 7 manual markers available, which generally occupy the sentence-initial position. The use of a manual marker is, however, not obligatory: we also found sentences without manual marker, in which only non-manual elements marked the conditional clause. What does this non-manual marking look like? The results show that, during the conditional clause, the eyebrows are often raised, and the head frequently shows a forward head movement and/or head tilt. Again, however, none of these signals is present throughout the whole dataset, thus, these non-manual markers are also not obligatory.
When we compare these results to descriptions of conditional clauses in other sign languages, the NGT results do not seem very striking, because manual markers and raised eyebrows have been shown to play an important role in other sign languages, too. For some of the characteristics, it seems as if NGT shows more variation, but it is important to keep the different research methodologies in mind: based on elicited data and translated sentences, one might be tempted to conclude, for example, that all conditional clauses will always be signed with raised eyebrows, whereas our naturalistic data clearly show that this is not the case. So, it is important to investigate naturalistic data, and analyze ample output from various signers.