It has been observed that some unusual word orders - referred to as ‘Main
Clause Phenomena’ (MCPs) - are used almost exclusively in main clauses.
Emonds (1969; E69) hypothesized that only in main clauses the long-distance
relations needed to produce MCPs can be established; Temperley (2019; T19)
proposed that MCPs occur in main clauses because those clauses tend to
appear in sentence-initial position where processing is easier than in
sentence-internal positions. Here, we aim to test these hypotheses with two
acceptability-judgement studies. Our findings are consistent with T19: MCPs
like locative inversion are easiest to process in sentence-initial
positions.