The memory load of assembling (Specifier)-Head-Complement(s) phrases in mono-clausal Subject-Verb-Object sentences was assessed by employing the click-detection paradigm a technique that has been shown to be sensitive to different cognitive loads within and between clauses in complex sentences. 60 pairs of Spanish sentences, containing a longer phrase in either the Subject or Object position were employed, and three click positions (controlled for length) were determined. Results show that reaction times are faster at the beginning of sentences, but there is a robust linear decrease in RTs between positions. An ANOVA analysis determined that both the sentence type and the click position factors are significant, but there is no interaction effect. Nevertheless, all within-sentence-type comparisons were significant, while only the second position (before or after the verb) proved to be significant across sentence-type, suggesting that the parser is generally more strained before the appearance of the verb.