Purpose clauses in LIS are typically introduced by the sign glossed goal, as in the following sentence where the purpose clause conveys the information that the reason why Maria goes to the store is that she wants to buy food.
maria store go goal food buy++
‘Maria goes to the store in order to buy food.’
Purpose clauses introduced by the sign goal canhave the make-up of finite declarative clauses, as shown by the fact that they can contain a specification of tense or aspect. For example, the purpose clause in the following sentence contains the aspectual marker to_be_done (the sign glossed to_be_done derives from the verb ‘must’ but is used as an aspectual marker here, as confirmed by the fact that a different sign, namely must, expresses the deontic meaning in the first part of the sentence, see LEXICON 3.3.2).
gianni mechanic car bring to_be_done goal overhaul
‘Gianni will take his car to the mechanic, so that he gets it serviced.’
The presence of specialised signs introducing purpose and reason clauses (goal and reason respectively) reduces the chances of ambiguity between these two types of clauses in LIS. For example, (a) and (b) below are not ambiguous. They express a reason meaning and a purpose meaning respectively.
a. gianniaixa car function not. look_for mechanic reason want fix holiday leave
‘Gianni’s car does not work. He is looking for a mechanic because he wants to have it fixed and leave for the holidays.’
b. gianni car function not. look_for mechanic goal fix ready can holiday leave
‘Gianni’s car does not work. He is looking for a mechanic so that it can be fixed and he can leave for the holidays.’