How can we identify "By the end of the next month I...... That place. " is future perfect tense. Also please explain how can we identify "They..... The room before he reaches here" is past perfect continues

Q no 5 second action simple presentil alle koduthittullath....athupole oronninum timing words koodi paranjirunnenkil kurachukoodi nallathayene.... Mal and Eng oro classinteyum avasanam vocabulary kurachu questions koodi thannal padikkan easy ayane....avasanam orumichu akumbol ellam ormayil varilla atha