tests by here4u with the online test builder (683 tests)

661. Relative pronouns (3153 candidates)
662. Prepositions and particles (1664 candidates)
663. Conditional present and past (26087 candidates)
664. Rephrasing and modals (11672 candidates)
665. For - since - ago and tenses (5933 candidates)
666. Use of tenses in a text (14219 candidates)
667. Rephrasing of verbs (4111 candidates)
668. Some forms of verbs (1829 candidates)
669. Prepositions and particles (1538 candidates)
670. To do or To make (2409 candidates)
671. To do or Not to do (1639 candidates)
672. A few difficult words (3084 candidates)
673. Question tags (1303 candidates)
674. Need of articles (2085 candidates)
675. Compound adjectives (2443 candidates)
676. Particles (1478 candidates)
677. From plural to singular (5247 candidates)
678. Particles (2027 candidates)
679. Question tags (1347 candidates)
680. Verbs in several tenses (3470 candidates)