Abstract Both ‘Educational Linguistics’ and ‘Pedagogical Linguistics’ have demonstrated the importance of linguistic knowledge in teaching/learning second/foreign languages. More recently, there have been concrete proposals that insights from formal linguistics and theoretical acquisition research may also play a role in pedagogy. Indeed, many observed difficulties in L2 can be traced back to lack of knowledge, on the part of teachers, of certain abstract linguistic concepts. In this paper, two English constructions (constructions with Object pronouns and DP-internal concord) claimed to be problematic for the learner/teacher in the absence of any linguistic knowledge will be investigated in terms of their abstract properties. The implication is that such linguistic knowledge will speed up the process of learning. This will be supported by previous findings on aspectual contrasts in English and Arabic where such knowledge clearly obtains, causing the learning process to be relatively rapid. Evidence for the presence of this knowledge in the learners comes from observation of the transitional stages in the learning process which indicate that the learner is on the right track to learning. The research hypothesis will be argued to have significant implications for teaching, and thus, if correct, will corroborate some recent findings.