tests by here4u with the online test builder (650 tests)

501. Future and Conditional (9367 candidates)
502. Numbers and dates... (Level 1) (18981 candidates)
503. Numbers and Dates... ( Level 2) (8120 candidates)
504. I'd better... I'd rather... (24078 candidates)
505. When : What tense to put behind... (31934 candidates)
506. Vocabulary: Animal sounds/cries (12426 candidates)
507. Vocabulary: Emergency - First aid... (29046 candidates)
508. Expressing time: by... , by the time..., once... (5985 candidates)
509. Before - In front of - Opposite... (8596 candidates)
510. Vocabulary: Swimming, diving... (2715 candidates)
511. Who - What - Which (24462 candidates)
512. Infinitive implied by its particle. (3373 candidates)
513. Doing, Do, To do... (9427 candidates)
514. Choosing your past tense... (48155 candidates)
515. Tenses : satisfying the request... (2) (2188 candidates)
516. The use of tenses: a strange request...(1) (3622 candidates)
517. Either...or/ Neither...nor/ Not ... either. (13526 candidates)
518. There is / are, and other forms... (5107 candidates)
519. To be / to have: -ing forms... (4315 candidates)
520. Enough with the Present Perfect... (21990 candidates)