Turkish: A Comprehensive Grammar

Tense, aspect and modality 321
(ii) The other function of -(y)DI is to indicate counterfactuality. This occurs only with the
modal forms olur (21.4.1.3), olabilir (21.4.2.1), olmalı (21.4.2.2) and olsa (21.4.4.1).
olmalıydı expresses an unfulfilled obligation (21.4.2.2). The reference is not
necessarily to a past time:
(197) Bu saatte çalışıyor olmalıydım.
‘I should/ought to be working at this time of day.’
In the case of the aorist there can be ambiguity between past and counter-factual
meaning. For example, (198) could be understood as expressing either a habitual state of
affairs in the past, or a state of affairs that did not occur but would have if some condition
had been fulfilled:
(198) Saat dörde kadar mektuplar postalanmış olurdu.
‘By four o’clock the letters would have been posted.’