tests by here4u with the online test builder (670 tests)

641. Forms of verbs (3153 candidates)
642. If clauses (5780 candidates)
643. Present simple or continuous (29352 candidates)
644. Present simple (11605 candidates)
645. Present continuous (8719 candidates)
646. Forms of verbs (7400 candidates)
647. V - ing or infinitive (5312 candidates)
648. Relative pronouns (3069 candidates)
649. Prepositions and particles (1656 candidates)
650. Conditional present and past (25444 candidates)
651. Rephrasing and modals (11626 candidates)
652. For - since - ago and tenses (5910 candidates)
653. Use of tenses in a text (14164 candidates)
654. Rephrasing of verbs (4082 candidates)
655. Some forms of verbs (1816 candidates)
656. Prepositions and particles (1534 candidates)
657. To do or To make (2403 candidates)
658. To do or Not to do (1623 candidates)
659. A few difficult words (3078 candidates)
660. Question tags (1300 candidates)