We report two reading experiments and two questionnaire studies design
ed to investigate the processing of ''sluiced'' sentences, like Somebo
dy left-guess who. A self-paced reading experiment showed that sentenc
es with explicit (overt) antecedents are read more quickly than senten
ces with implicit (covert) antecedents, both when the antecedents in q
uestion were arguments and when they were adjuncts. An eye movement ex
periment showed that sluiced sentences containing two potential antece
dents were read faster than sentences containing only a single anteced
ent in matrix subject position. We suggest this is because only the am
biguous sentences contained an antecedent in a normal focus position (
embedded object position). Two questionnaire studies suggested that pe
rceivers prefer a focused constituent as the antecedent of the sluiced
constituent. Since we argue that the interpretation of a sluiced cons
tituent take place at the representational level of ''logical form'' (
LF), we conclude that implicit arguments are not made explicit at LF b
ut that focus is important in the processing of LF.