3.5.5. Reason clauses
Reason clauses (also called causal clauses) are subordinate clauses that typically give a reason for the event expressed in the main clause, as in the following sentence: ‘I called you because I missed you’. Here, the reason clause is introduced by ‘because’.
The reason clause may also provide the reason for the belief the speaker has towards the event expressed in the main clause. For example, by uttering the sentence ‘It (must have) snowed, since the street is white’, the speaker does not assert that the reason of snowing is the whiteness of the street, but (s)he is inferring that it snowed from the fact that the street is white.
Reason clauses have something in common with purposes clauses (SYNTAX 3.5.6), since they both express some sort of explanation for the event expressed in the main clause. This is why in some languages, including Italian (but not LIS), they can be introduced by the same marker (perché ‘so that’, ‘because’).
(i) Ti ho chiamato perché andassi in banca
(I) you have called so-that (you) go(SUBJ) to bank
‘I called you so that you would go to the bank.’
(ii) Ti ho chiamato perché eri andato in banca
(I) you have called because (you) had gone to bank
‘I called you because you had gone to the bank.’
Sentence (i) expresses the purpose of the event of calling and the verb in the purpose clause is subjunctive. Sentence (ii) expresses the reason that triggered the event of calling and the verb in the reason clause is indicative. Notice that in sentence (i) the event expressed in the purpose clause (going to the bank) is unrealized at the time of the main event (the calling), whereas the event in the reason clause is realized in (ii). This suggests a way to distinguish the two types of clauses: the event expressed by the purpose clause cannot precede the event in the main clause, while this restriction does not apply to reason clauses.
Still, in Italian there can be cases where the same clause can be interpreted either as a reason clause or as a purpose clause. This happens in the following sentence where the non-finite clause can express either the reason why someone went to the store or the purpose of the visit to the store.
È andato al supermercato per fare la spesa
(he) is gone to.the store to-do the shopping
‘He went to the store to do shopping’
‘He went to the store because he wanted to do shopping’
