Another site:
AllTop 200 most popular tests to learn English...
1) Test de niveau anglais (webmaster) 6 779 746
2) Placement test : grammar for beginners (anonyme) 5 994 337
3) A/AN (webmaster) 5 366 861
4) Auxiliary BE (webmaster) 3 225 070
5) Present continuous (webmaster) 3 000 136
6) Present simple (webmaster) 2 917 110
7) Present simple (webmaster) 2 598 431
8) Present continuous (webmaster) 2 436 074
9) Adjectives (webmaster) 2 094 104
10) A/an (anonyme) 2 016 216
11) Present perfect simple (webmaster) 1 644 888
12) Preterite (webmaster) 1 629 963
13) Vocabulary - Placement test (bridg) 1 619 597
14) Preterite (webmaster) 1 448 786
15) Short placement test (webmaster) 1 443 968
16) To be (bridg) 1 406 764
17) What time is it? (webmaster) 1 349 870
18) Present perfect (webmaster) 1 347 322
19) The alphabet in English (webmaster) 1 321 595
20) Adjectives (anonyme) 1 216 403
21) What time is it? (webmaster) 1 209 269
22) Numbers (webmaster) 1 188 879
23) 'A' ou 'An' (anonyme) 1 176 220
24) Two presents: present continuous, present simple (webmaster) 1 149 940
25) To be (bridg) 1 145 959
26) Comparatives / Superlatives (webmaster) 1 105 433
27) Numbers (webmaster) 1 071 173
28) CAN / MUST (webmaster) 1 059 003
29) THE/ A / AN / nothing (webmaster) 1 034 365
30) Comparatives (webmaster) 1 007 575
31) Family life (bridg) 1 001 256
32) Numbers > 100 (webmaster) 986 761
33) Future (going to/will/present continuous) (anonyme) 964 594
34) Plural (webmaster) 956 131
35) Superlatives (webmaster) 875 628
36) Adjectives (anonyme) 875 161
37) Simple present (bridg) 854 343
38) Spelled words N°1 (bridg) 850 517
39) Placement test beginners: Check your spelling (anonyme) 830 248
40) Introducing oneself (webmaster) 827 412
41) Adverbs of frequency (anonyme) 817 994
42) Family (bridg) 785 117
43) General test-End of high school / Beginning of university (webmaster) 783 089
44) Present simple (anonyme) 781 530
45) Frequency adverbs (webmaster) 778 043
46) Present BE + Ving (bridg) 765 510
47) Passive form (anonyme) 724 017
48) Genitive (webmaster) 723 931
49) Family tree (anonyme) 719 695
50) Preterite: simple or continuous? (webmaster) 717 158
51) Placement test (beginners) (lili73) 701 490
52) Past simple or present perfect (anonyme) 694 762
53) Future (webmaster) 676 173
54) 2 Preterites (webmaster) 662 476
55) Present perfect simple (bridg) 662 024
56) Preterite (webmaster) 620 870
57) List of 200 irregular verbs and audio (bridg) 616 376
58) Modals (webmaster) 612 980
59) Spelled words N°2 (bridg) 609 469
60) Height (webmaster) 606 546
61) Modals (webmaster) 606 133
62) Articles a / an / the (anonyme) 596 766
63) Plural forms (bridg) 577 770
64) Nationalities (webmaster) 574 491
65) Past continuous / Past simple (anonyme) 567 100
66) Irregular plurals (bridg) 553 911
67) Two presents: simple and continuous (webmaster) 549 896
68) Preterite (bridg) 549 294
69) Superlatives (frapedur) 539 619
70) Vocabulary: greeting people (here4u) 536 502
71) Give your opinion (bridg) 532 226
72) Adverbs of Frequency (bridg) 517 184
73) Present simple or continuous (anonyme) 511 767
74) Present perfect / preterite ? (anonyme) 510 189
75) Possessive case (anonyme) 480 874
76) Countries & nationalities (bridg) 473 738
77) 'The' or nothing? (webmaster) 471 390
78) Past tenses (bridg) 471 200
79) Introducing oneself (easy) (webmaster) 470 872
80) Passive voice (webmaster) 463 812
81) Present Simple vs. Past Simple (anonyme) 458 013
82) Questions : how to ask them (anonyme) 448 638
83) General Test II / End of high school / Beginning of universi (webmaster) 446 285
84) IN, ON, AT or TO? (webmaster) 445 571
85) Relative pronouns (webmaster) 444 770
86) Comparative of superiority (anonyme) 439 024
87) How to pronounce the final -ED? (past simple) (webmaster) 438 220
88) Relative clauses (webmaster) 423 578
89) Sounds: [h] (webmaster) 419 638
90) Comparative (anonyme) 414 028
91) A/an/Ø (bridg) 399 038
92) Past simple (anonyme) 397 989
93) Future simple (anonyme) 396 646
94) This / That / These / Those (webmaster) 392 711
95) Conditional (webmaster) 391 904
96) Passive voice (anonyme) 390 911
97) Comparing (webmaster) 388 164
98) Can / could/ may/ might (woodyrun) 379 862
99) Present perfect or past tense (anonyme) 377 770
100) Much, many, little and few (felin) 373 131
101) Personal pronouns (anonyme) 371 408
102) Preterite continuous (BE + -ING) (webmaster) 369 643
103) Some, any, no, enough, too/too much/too many (webmaster) 368 313
104) Genitive case (bridg) 368 308
105) Confusing words - Placement test (bridg) 364 604
106) Irregular verbs (webmaster) 363 766
107) Numbers from 1 to 10 (anonyme) 361 657
108) Past perfect simple, past perfect continuous (anonyme) 360 989
109) Present continuous or present simple (webmaster) 359 722
110) Present perfect or preterite? (anonyme) 357 199
111) Simple Past : regular verbs (anonyme) 353 401
112) Comparative Adjectives (bridg) 352 386
113) Who, Whom, Which, or Whose? (anonyme) 348 965
114) Past simple (video) (anonyme) 348 648
115) Past simple or past continuous (anonyme) 343 190
116) While / When (anonyme) 339 266
117) What time is it? (webmaster) 338 130
118) Modals (tinou) 336 688
119) Modal: may/might (anonyme) 334 321
120) Cardinal and ordinal numbers (anonyme) 328 856
121) The superlative (anonyme) 325 925
122) Possessive adjectives and pronouns (woodyrun) 324 445
123) How to talk about the weather (lili73) 320 911
124) Since and for (anonyme) 319 007
125) Flags (webmaster) 317 698
126) Irregular verbs (bridg) 316 154
127) Prepositions - in, on, at (anonyme) 314 212
128) Pronouns (woodyrun) 313 895
129) Tenses (anonyme) 312 138
130) Placement test 3 (webmaster) 310 651
131) Order of adjectives (webmaster) 306 689
132) Could/Couldn't (laure95) 306 012
133) Comparative (anonyme) 304 814
134) Agreement Tags (webmaster) 304 162
135) Adjectives and prepositions (anonyme) 304 122
136) Asking questions (webmaster) 303 288
137) Present perfect OR simple past? (bridg) 298 502
138) Questions in the past tense (anonyme) 297 690
139) Superlative Adjectives (bridg) 295 932
140) Uncountable nouns (webmaster) 295 874
141) Object pronouns (bridg) 295 146
142) Placement test 1 (anonyme) 292 921
143) Passive form (anonyme) 291 670
144) Present simple (anonyme) 291 461
145) Can/Must/Should (laure95) 289 792
146) Prefer/rather (bridg) 289 577
147) Past perfect (lili73) 288 559
148) Must or Have to? (woodyrun) 287 715
149) The/an/nothing (bridg) 285 380
150) To be (anonyme) 283 530
151) Can and can't (laure95) 281 817
152) Vocabulary: asking and answering (here4u) 280 459
153) Modal verbs (bridg) 277 362
154) Some / Any / no... (bridg) 273 339
155) Days of the week (bridg) 269 118
156) So / neither (anonyme) 264 403
157) Past simple (video) (anonyme) 263 820
158) Present continuous (chnawa) 260 568
159) Used to (bridg) 260 431
160) Should / must (anonyme) 259 792
161) Past tense (anonyme) 259 421
162) Vocabulary: on the phone (here4u) 258 766
163) Find out a quantity (webmaster) 258 613
164) Superlative + and adjective (anonyme) 257 349
165) Articles : a / an / the / Ø (anonyme) 257 146
166) Comparative and superlative (anonyme) 255 616
167) Numbers 1/100 (anonyme) 253 713
168) Modal can (video) (anonyme) 253 072
169) Comparatives (anonyme) 248 805
170) Relatives pronouns (who, which, that...) (anonyme) 247 849
171) Vocabulary: at the restaurant (here4u) 245 675
172) A few, a little, few, little (anonyme) 245 604
173) Would rather / would prefer to (anonyme) 244 429
174) Present continuous and the Going to form (anonyme) 242 758
175) Should/ have to/ must (anonyme) 240 117
176) Have something done (anonyme) 239 895
177) The past (webmaster) 237 887
178) Used to/would (woodyrun) 237 701
179) Future continuous and future perfect. (felin) 237 679
180) How to ask a question in English (bridg) 235 567
181) I wish, if only (felin) 234 114
182) Pluperfect (webmaster) 234 032
183) Countable or Uncountable? (webmaster) 233 280
184) Some / any (younes91) 233 017
185) Should / shouldn't (anonyme) 231 603
186) Present simple or continuous (bridg) 230 804
187) Adjectives - ing and ed (felin) 229 168
188) Hypothesis (webmaster) 228 284
189) Auxiliary BE (anonyme) 226 484
190) Articles a/an/the/0 (bridg) 226 338
191) Article The or nothing (anonyme) 226 025
192) Must or mustn't (laure95) 225 813
193) Present perfect with Ever - never - (anonyme) 225 650
194) Present continuous OR Present simple? (bridg) 225 545
195) Simple Preterite OR Preterite (BE+ing) (webmaster) 222 869
196) To / in order to / so as to / so that (irish21) 220 483
197) Present perfect (bridg) 219 545
198) Comparison (komiks) 219 108
199) What time is it ? (anonyme) 217 704
200) Indirect speech (bridg) 216 766
