In three structural priming experiments, participants read a prime sentence aloud, followed by a target fragment that they had to complete. In Experiments 1 and 2, participants had to complete the targets by using words for pictures that were simultaneously presented, whereas in Experiment 3, there were no pictures. We manipulated (1) the prime structure (prepositional object/PO or double object ditransitive/DO structure, e.g., the painter hesitated to lend the apprentice the ladder or the painter hesitated to lend the ladder to the apprentice) and (2) whether the matrix verb in the prime (e.g., hesitated) was repeated in the target (e.g., The farmer hesitated to show …). In Experiment 1, the prime and target verbs were relatively frequent, whereas in Experiments 2 and 3, they were less frequent. As the dependent variable, we scored whether participants completed the target fragments with a prepositional object or double object structure.Three structural priming experiments investigated whether the lexical boost is due to the repeated head verb of the primed structure or due to the repetition of any verb. We tested structural priming of ditransitive structures (the painter hesitated to lend the apprentice the ladder/the ladder to the apprentice) and manipulated the repetition of the matrix verb (hesitated) that is not the syntactic head of the primed structure. In two experiments, participants read aloud prime sentences (e.g., The farmer vowed to show …) and then described pictures by completing a sentence fragment in the target. In the third experiment, the pictures were removed from the targets and the participants were free to complete the sentence fragments in the way they wanted. All experiments showed abstract structural priming of the ditransitive structure but the repetition of the matrix verb did not boost priming. The third experiment also showed that it did not matter for priming whether participants' sentence completion was constrained by pictures or they could complete the sentence fragments without any constraints.

Behavioural experiment. Participants were students from the University of Dundee who were native speakers of English and had no known reading or language difficulties. The study was approved by the University of Dundee ethics committee and all participants gave informed consent to take part in the study. Experiment 1 tested 40 participants, Experiment 2 56 participants and Experiment 3 40 participants. In Experiments 1 and 2, participants read a prime sentence aloud and next completed a target sentence fragment using pictures. In Experiment 3, the target pictures were omitted. In all experiments, participants were asked to complete the sentences in a meaningful and grammatical way.