Tenses and prepositions MCQ - Practice Questions with Answers

The sentence needs the present perfect, because the relationship began in the past and continues up to the present: “I have known her.” A duration such as “a long time” takes “for”, while a starting point or reference time such as “she was a child” takes “since”. “Know, since, for” reverses the prepositions and uses the wrong tense. “Knew” suggests only a past relationship and leaves the duration phrase unsupported. “Was knowing” is not idiomatic here, and “since a long time” is incorrect in standard English.