Questions & Answers about Filmin kurgusunu anlamıyor değilim.
How does the double negation anlamıyor değilim work in this sentence?
The verb anlamıyor means 'not understanding,' and adding değilim ('I am not') creates a double negative: 'I am not not-understanding.' This softens the affirmation. Instead of a direct 'I understand it,' it means 'It is not that I don't understand it,' strongly implying you do understand the plot, but there is likely a contrasting thought coming next, such as '...but I still didn't like it.'
Why does kurgu (plot) take the ending -sunu instead of just the accusative -yu?
Because it is part of a possessive noun compound. Filmin kurgusu means 'the movie's plot,' using the genitive suffix -in on film and the possessive suffix -su on kurgu. Since this entire phrase is the specific direct object of the verb anlamak, we must add the accusative suffix -u. The buffer letter -n- is always used between a third-person possessive suffix and a case marker, resulting in kurgusunu.
Could I use the aorist tense and say anlamaz değilim instead?
Yes, you can use the negative aorist, but it changes the nuance slightly. Anlamaz değilim translates closer to 'It is not that I generally do not understand.' In this sentence, anlamıyor değilim uses the present continuous tense (-yor) because it sounds much more natural when discussing your current, specific state of mind regarding a particular movie you just watched.