Questions & Answers about Я не помню название этого фильма.
Помнить means to remember or to have in memory, while знать means to know.
So:
- Я не помню название этого фильма = I don’t remember the title of this film
- Я не знаю название этого фильма would mean I don’t know the title of this film
In English, I don’t remember and I don’t know can sometimes feel similar, but in Russian they are usually kept distinct.
Название is the direct object of помню, so it goes in the accusative case.
However, название is a neuter inanimate noun, and for neuter inanimate nouns, the accusative form is identical to the nominative.
So:
- nominative: название
- accusative: название
That is why the word does not visibly change.