Some early experiments (Clark and Clark 1968;Smith and McMahon 1970) have really shown that on a sentence verbatim recall task normal adults made significantly fewer errors remembering the sense of 'Main-Sub' sentences, as in (1b, d), than of ' as in (1a,c).
studies of normal adults (Smith and McMahon 1970), kindergarten-and school-age children (Clark 1971;Natsopoulos and Abadzi 1986), and aphasics with relatively preserved auditory comprehension (Ansell and Flowers 1982) indicated that on a sentence comprehension task clause order did not significantly affect the comprehension accuracy.