I know that "have to" in English, as in "I have to do it" (expression of obligation), should be translated using the verb "devoir". So "I have to do it" would be "Je dois le faire". In the same vein, ...
En anglais, je dirais « I have been reading this book all day » ou « I have been working on it since yesterday. » Comment peut-on le dire en français? Franchement, quand j'essaie de le traduire en ...