To narrow down who could have done something or to estimate a maximum limit, use the reduplicated conditional.
Take the verb stem, add the conditional suffix -sa or -se (following 2-way vowel harmony), and repeat the word. For example, açmak (to open) becomes açsa açsa.
The sentence usually ends with the exact same verb, conjugated for time. If you are deducing a past event, the final verb often takes the confident guessing suffix -mIştIr. If you are estimating a general truth or future limit, the final verb usually takes the aorist (the wide tense).
Narrowing Down Suspects
When trying to solve minor mysteries or figure out who is responsible for an action, this structure translates roughly to "if anyone were to do this, it would only be..." or "only [X] could have..."
Upper Limits and "At Best"
When applied to locations, outcomes, or companions, this structure lowers expectations. It translates to "at most" or "at best," estimating the absolute upper limit of a situation.
Deducing Motives and Behavior
You can also use this pattern to deduce the only logical reason behind someone's behavior, especially when strong emotions dictate their actions.
Physical Capacity
Finally, this grammatical doubling works perfectly for estimating the physical limits of an object. In Turkish, the verb almak (to take) is also used to describe how much a container can hold.