The role of directives with command and question speech functions in teaching and learning contexts has received increased attention across a number of disciplines in recent years. This current study was aimed at investigating the use and function of directives with command and question speech functions as a dimension of interpersonal realization in aerospace engineering lectures at Delft University of Technology, Netherlands. Focusing on the English mood system, this study applied Halliday’s (1985, 1994) and Eggins’s (1994) Systemic Functional Linguistics (SFL) approach. A qualitative content analysis was carried out in four selected content lessons. The data were collected through videotaped recordings as found at cosmolearning.org. The findings showed that engineering lecturers employed various types of directives. In terms of commands, the lecturers used imperative, declarative, and modulated interrogative moods. In addition, lecturers used interrogative and declarative moods to pose questions. The lecturers used commands to express their attitudes, to organize their messages, to check students’ understanding, and to signal the contents of the exams. Meanwhile, in terms of questions, they function to elicit students’ background knowledge, to check on students’ comprehension, and to handle classroom management issues. The findings of this study can be used by English for Academic Purposes (EAP) professionals, in particular, language lecturers preparing students for the English for Medium Instruction (EMI) study. Also, stakeholders should use the findings of this study as a tool to improve English for English Special Purposes (ESP) teaching and learning in the context of the engineering classroom.