The rules for when purpose clauses must take subjects or objects are not given by Okrand. In general, it appears that purpose clauses attached to verbs (sentences) get subjects (possibly indefinite) and objects, while those attached to nouns don't. But he's broken that general trend from time to time (qaSuchmeH 'eb; qIpmeH Qatlh'a'; and even the object-but-no-subject SuvwI' DevmeH paq).

Though this last might be interpreted as a noun-noun construction between the noun SuvwI' and the noun phrase DevmeH paq, so forget that one as an exceptional case.

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SuStel
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