The aim of the present study was to analyse leaners’ use of logical connectors within the EFL classroom setting as well as to provide insights into the effects of instruction on their acquisition process. To this aim, two different types of instructional treatments (i.e. explicit versus implicit) were implemented on two groups of secondary school learners’ to determine progress in the use of logical connectors by comparing the two teaching approaches. The explicit instructional approach was operationalised on the basis of the principles underlying the "focus on form" paradigm providing extensive opportunities for communicative practice together with an explicit type of feedback. In contrast, the implicit one provided learners with exposure to the target items by means of reading comprehension passages and vocabulary work, with fewer opportunities for productive use of the language and an implicit type of feedback. Results showed that both types of instructional treatments proved to be beneficial for learners increasing their use of connectors in written texts. However, the approach that incorporated an explicit focus on form proved to be more effective to enhance learners’ accurate production of the target items. In addition to this, the study also focuses on task demands (free or controlled) regarding accuracy in connector use. Finally, wrong uses of connectors are analysed taking into account aspects such as function and/or type of connector in an attempt to create a taxonomy of logical connector errors. It is suggested that specific types of errors may be found within local or global discourse levels affecting learners’ discourse competence in various ways.