An important strategy for understanding and interpreting meanings and intentions in texts is the knowledge of the reasons why the writer opted between active and passive constructions. In this respect, SWAN (2008:410) comments that: “In a passive clause, we usually use a phrase beginning with by if we want to mention the agent ‒ the person or thing that does the action, or that causes what happens. (Note, however, that agents are mentioned in only about 20 per cent of passive clauses.)” In text II, the passive construction is employed several times, as in: “[…] so that words are recognized automatically.” (§ 2) “These word recognition strategies are taught as children […]” (§ 2) “[…] a strategy between the two languages that has been demonstrated to be effective […]” (§ 4) The explanation for the omission of the passive by‐agent in these sentences is found in: