First language acquisition studies reveal that children overextend theminimal distance principle(MDP) during their acquisition of infinitive complement structures. The MDP dictates the interpretation of the logical subject of the infinitive in these structures and overrides marked lexical features such assubject control.Misinterpretations by adult second language learners and by adult prelingually deaf individuals are also shown to result from an overextension of the MDP. On a comprehension test of specific sentences, the relative order of difficulty in interpreting the logical subject of the infinitive is similar for both groups. This order reflects the same order of difficulty on sentences containingtell, ask, andpromisewhich has been reported in the literature on first language acquisition. The later acquisition of certain structures is explained in terms of the inherent linguistic complexity of the sentences.