The Tense That Looked Right
A B1 gap-fill item: "When I arrived at the station, the train ______ (leave)." The intended answer is 'had left'. A candidate, Tomás, writes 'left'. His teacher asks him to explain. Tomás says: "Both are past, and 'left' sounds fine to me. In my language we use the same past form for both events, so I don't hear the difference." He can, however, correctly produce 'had left' when the sentence includes 'already' or 'by the time I got there'. He also writes 'has left' in about one in five attempts at this item.
1. Is Tomás's error a knowledge gap or a performance/transfer issue? Justify using the evidence in the setup.
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Mostly performance/transfer, with a small residual knowledge gap.
Evidence for transfer: he produces 'had left' correctly when a lexical cue ('already', 'by the time') is present. That shows the form and its meaning are available to him; what is missing is automatic detection of the cue from the time relationship itself. His first language uses one past form for both events, so his default parser does not flag the sequencing.
Evidence for a residual gap: the 'has left' variants (about 20%) suggest the present-perfect form is also competing, i.e. his map of past-perfect vs present-perfect is not fully stable. That is a genuine, if narrow, knowledge issue.
So: teach the concept (which event happened first) alongside the form, rather than drilling the form alone.
2. Design a short correction activity that targets the real problem, and state what evidence would show it worked.
Read the worked answer
Activity - 'which came first?' ordering. Give 8 pairs of past events with no time words, e.g. 'I reached the platform. / The train left.' Ask Tomás to decide the order and then write one sentence with the correct forms, forcing him to choose the tense from meaning, not from a cue word. Then repeat with the cue words removed from sentences he previously got right, so he must supply the logic himself.
Add a small contrast set for the perfect forms: three sentences where 'has left' is correct (present relevance) versus three where 'had left' is correct (earlier past), and ask him to justify each.
Success evidence: (1) accuracy on cue-free items rises toward his cued accuracy; (2) 'has left' substitutions drop below roughly 5%; (3) he can state the rule in his own words - 'the earlier event takes had + past participle' - which is the marker that the concept, not just the pattern, has been acquired.