This is the 13th most frequent Hungarian word.
sem
The Hungarian word "sem" means "neither" or "nor."
In this sentence, 'sem' is used to indicate 'neither', showing an additional negative statement related to the previous clause.
Nem tanultam magyarul, és a barátom sem.
I haven't learned Hungarian, and neither has my friend.
Here, 'sem' is applied similarly to connect another element (the movie) to the negation initiated by the first statement (the book not being interesting).
A könyv nem volt érdekes, és a film sem.
The book wasn't interesting, and neither was the movie.
'Sem' is used in the form 'sem...sem' to indicate 'neither...nor', associating multiple items with a negative context.