As I understand it, all the sentences may be used. But I don't understand when there is need to add "to be" after "is considered". Could you explain the nuances of these examples, please? For me, the first sentence & the third one are absolutely the same.
(From Ngram I see that the first one is more common.)
French is considered the language of love.
French is considered to be the language of love.
French is considered as the language of love.
P.S. From my online course I have received a sentence: French is considered to be a language of love. I think it's a mistake because there is said about the certain category of language.
Best Answer
In your examples, the phrase to be is often elided. The sentence is perfectly correct either way.
However, if you were talking about a historical figure, you would usually omit to be as it implies that the person is still alive.
I say usually because historical figures are sometimes reanimated, as in: Shakespeare is considered to be the world's greatest playwright. One comes across this construction in the place of the more correct to have been because the comparison includes playwrights both living and dead.
Is considered as is an alternative way of saying the same thing.
I don't see any problem with your example about French as a language of love, although it would more usually be phrased as the language of love.