If I understood correctly, "until now" can be "until then" in the past sentences. Would this be correct? it was a new approach that was never successfully performed until then. or should I ...
I've been wondering recently, the past perfect tense (the "have"+particip form) seems to be used both less in American English than in "European" English and in "Latino" Spanish than in "European" ...
I know there is difference between these tenses in sentences like: -I have broken my leg so now I cannot walk - present perfect (I did something in past and second part of sentence show consequences) ...