tests by here4u with the online test builder (669 tests)

641. If clauses (5778 candidates)
642. Present simple or continuous (29341 candidates)
643. Present simple (11602 candidates)
644. Present continuous (8719 candidates)
645. Forms of verbs (7399 candidates)
646. V - ing or infinitive (5309 candidates)
647. Relative pronouns (3068 candidates)
648. Prepositions and particles (1656 candidates)
649. Conditional present and past (25440 candidates)
650. Rephrasing and modals (11624 candidates)
651. For - since - ago and tenses (5910 candidates)
652. Use of tenses in a text (14161 candidates)
653. Rephrasing of verbs (4082 candidates)
654. Some forms of verbs (1816 candidates)
655. Prepositions and particles (1534 candidates)
656. To do or To make (2403 candidates)
657. To do or Not to do (1623 candidates)
658. A few difficult words (3078 candidates)
659. Question tags (1300 candidates)
660. Need of articles (2079 candidates)