SAKIR is often governed by the preposition FYRIR. However, that is not always the case -- then it is parsed as projecting a PP with a silent preposition, like MÓTI. Therefore, SAKIR (or SÖKUM) is always tagged as NS, projecting an NP.
( (IP-MAT-SPE (CONJ og-og) (PP-LFD (P 0) (NP (NS-A sakir-sök) (NP-POS (PRO-G þess-það)))) (ADVP-RSP (ADV þá-þá)) (VBPI býð-bjóða) (NP-SBJ (PRO-N eg-ég)) (NP-OB2 (PRO-D þér-þú)) (PP (P á-á) (NP (N-A hólm-hólmur)))) (ID 1400.VIGLUNDUR.NAR-SAG,.282))
Examples of SAKIR, with and without an overt preposition: Hann gerði þetta fyrir sakir ódugnaðar 'He did that for sake of inefficiency'; Hann gerði þetta sakir ódugnaðar 'He did that sake of inefficiency'.
(PP (P fyrir-fyrir) (NP (NP-POS (N-G hræðslu-hræðsla)) (NS-A sakir-sök)))