- Je pense que ce film était amusant.
When I was making corrections to someone's notebook, I hold a strange feeling in this sentence because the sentence's paraphrase in Japanese is like this.
This Japanese doesn't seem to have any flaws in it. But I remind myself when I do say like this. I will never say like that because I just say
This phrase in English is like this
- I think the movie was fun.
Does this cause you any such feelings as I felt?
In contrast, it will never look strange if it would be like this.
- Je pensait que ce film était amusant.
- I thought the movie was fun.
I think Japanese native-speaker ever corrected me writing : その映画は面白いだと思いました。
But I think, in class, I have ever seen the sentence wrote like in your exemple :S maybe we learn a correct but non-natural Japanese. it's equivalent in french, saying : "Je pensais que c'était un film amusant" is completely correct, but we rather say :" j'ai trouvé ce film amusant."
"Je pensais que c'était un film amusant" can suggest both the idea that you did think the movie was fun and the idea that you thought the movie was fun ( but it is actually not ). （その映画は面白いだと思ったけど。。。）
You can also say that to be sarcastic, changing the tone of the sentence ( as far as there are tones in French hahaha, I feel like my mother tongue is the flattest in the word )
Languages are so nuanced and elusive :)