Another site:
AllTop 200 most popular tests to learn English...
1) Test de niveau anglais (webmaster) 6 775 396
2) Placement test : grammar for beginners (lucile83) 5 986 943
3) A/AN (webmaster) 5 362 072
4) Auxiliary BE (webmaster) 3 222 719
5) Present continuous (webmaster) 2 997 321
6) Present simple (webmaster) 2 908 296
7) Present simple (webmaster) 2 595 641
8) Present continuous (webmaster) 2 430 532
9) Adjectives (webmaster) 2 092 621
10) A/an (anonyme) 2 013 569
11) Present perfect simple (webmaster) 1 639 934
12) Preterite (webmaster) 1 623 171
13) Vocabulary - Placement test (bridg) 1 618 433
14) Preterite (webmaster) 1 444 513
15) Short placement test (webmaster) 1 442 801
16) To be (bridg) 1 405 240
17) What time is it? (webmaster) 1 348 261
18) Present perfect (webmaster) 1 343 431
19) The alphabet in English (webmaster) 1 320 172
20) Adjectives (lucile83) 1 215 003
21) What time is it? (webmaster) 1 206 554
22) Numbers (webmaster) 1 188 061
23) 'A' ou 'An' (anonyme) 1 174 164
24) Two presents: present continuous, present simple (webmaster) 1 148 215
25) To be (bridg) 1 144 756
26) Comparatives / Superlatives (webmaster) 1 100 856
27) Numbers (webmaster) 1 069 839
28) CAN / MUST (webmaster) 1 057 917
29) THE/ A / AN / nothing (webmaster) 1 032 097
30) Comparatives (webmaster) 1 006 568
31) Family life (bridg) 999 991
32) Numbers > 100 (webmaster) 985 877
33) Future (going to/will/present continuous) (anonyme) 962 417
34) Plural (webmaster) 955 078
35) Superlatives (webmaster) 874 337
36) Adjectives (anonyme) 874 102
37) Simple present (bridg) 853 072
38) Spelled words N°1 (bridg) 849 519
39) Placement test beginners: Check your spelling (lucile83) 829 756
40) Introducing oneself (webmaster) 826 764
41) Adverbs of frequency (lucile83) 816 146
42) Family (bridg) 784 070
43) General test-End of high school / Beginning of university (webmaster) 782 176
44) Present simple (lucile83) 778 946
45) Frequency adverbs (webmaster) 777 260
46) Present BE + Ving (bridg) 764 301
47) Genitive (webmaster) 723 073
48) Family tree (anonyme) 718 903
49) Passive form (lucile83) 717 180
50) Preterite: simple or continuous? (webmaster) 715 659
51) Placement test (beginners) (lili73) 700 362
52) Past simple or present perfect (lucile83) 692 541
53) Future (webmaster) 675 472
54) 2 Preterites (webmaster) 661 167
55) Present perfect simple (bridg) 659 000
56) Preterite (webmaster) 619 410
57) List of 200 irregular verbs and audio (bridg) 615 403
58) Modals (webmaster) 612 313
59) Spelled words N°2 (bridg) 608 700
60) Height (webmaster) 606 006
61) Modals (webmaster) 604 177
62) Articles a / an / the (lucile83) 596 738
63) Plural forms (bridg) 576 842
64) Nationalities (webmaster) 573 824
65) Past continuous / Past simple (anonyme) 564 498
66) Irregular plurals (bridg) 553 068
67) Two presents: simple and continuous (webmaster) 549 106
68) Preterite (bridg) 548 377
69) Superlatives (frapedur) 536 624
70) Vocabulary: greeting people (here4u) 536 435
71) Give your opinion (bridg) 531 468
72) Adverbs of Frequency (bridg) 516 574
73) Present simple or continuous (lucile83) 509 397
74) Present perfect / preterite ? (anonyme) 507 753
75) Possessive case (anonyme) 480 183
76) Countries & nationalities (bridg) 472 937
77) 'The' or nothing? (webmaster) 470 923
78) Introducing oneself (easy) (webmaster) 470 424
79) Past tenses (bridg) 470 147
80) Passive voice (webmaster) 462 242
81) Present Simple vs. Past Simple (anonyme) 455 781
82) Questions : how to ask them (lucile83) 447 821
83) General Test II / End of high school / Beginning of universi (webmaster) 445 812
84) IN, ON, AT or TO? (webmaster) 444 578
85) Relative pronouns (webmaster) 443 725
86) Comparative of superiority (lucile83) 437 472
87) How to pronounce the final -ED? (past simple) (webmaster) 436 659
88) Relative clauses (webmaster) 422 876
89) Sounds: [h] (webmaster) 419 248
90) Comparative (anonyme) 412 707
91) A/an/Ø (bridg) 398 158
92) Future simple (lucile83) 395 616
93) Past simple (anonyme) 395 117
94) This / That / These / Those (webmaster) 392 206
95) Conditional (webmaster) 391 201
96) Passive voice (anonyme) 389 922
97) Comparing (webmaster) 387 743
98) Can / could/ may/ might (woodyrun) 378 979
99) Present perfect or past tense (anonyme) 376 458
100) Much, many, little and few (felin) 371 873
101) Personal pronouns (anonyme) 371 169
102) Preterite continuous (BE + -ING) (webmaster) 368 265
103) Some, any, no, enough, too/too much/too many (webmaster) 367 868
104) Genitive case (bridg) 367 475
105) Confusing words - Placement test (bridg) 364 400
106) Irregular verbs (webmaster) 363 133
107) Numbers from 1 to 10 (lucile83) 361 253
108) Past perfect simple, past perfect continuous (anonyme) 360 697
109) Present continuous or present simple (webmaster) 359 324
110) Present perfect or preterite? (anonyme) 355 911
111) Simple Past : regular verbs (anonyme) 352 184
112) Comparative Adjectives (bridg) 351 928
113) Who, Whom, Which, or Whose? (anonyme) 348 367
114) Past simple (video) (lucile83) 347 675
115) Past simple or past continuous (lucile83) 340 983
116) While / When (anonyme) 337 846
117) What time is it? (webmaster) 337 432
118) Modals (tinou) 336 246
119) Modal: may/might (lucile83) 333 906
120) Cardinal and ordinal numbers (anonyme) 328 450
121) The superlative (anonyme) 324 065
122) Possessive adjectives and pronouns (woodyrun) 323 814
123) How to talk about the weather (lili73) 320 851
124) Since and for (lucile83) 318 272
125) Flags (webmaster) 317 266
126) Irregular verbs (bridg) 315 632
127) Prepositions - in, on, at (anonyme) 313 900
128) Pronouns (woodyrun) 312 778
129) Tenses (anonyme) 311 455
130) Placement test 3 (webmaster) 310 176
131) Order of adjectives (webmaster) 306 329
132) Could/Couldn't (laure95) 305 594
133) Comparative (anonyme) 304 118
134) Adjectives and prepositions (lucile83) 303 876
135) Agreement Tags (webmaster) 303 794
136) Asking questions (webmaster) 302 847
137) Present perfect OR simple past? (bridg) 298 096
138) Questions in the past tense (lucile83) 297 146
139) Superlative Adjectives (bridg) 295 466
140) Uncountable nouns (webmaster) 295 307
141) Object pronouns (bridg) 294 269
142) Placement test 1 (lucile83) 292 460
143) Present simple (lucile83) 290 502
144) Passive form (anonyme) 289 549
145) Prefer/rather (bridg) 289 022
146) Can/Must/Should (laure95) 288 645
147) Past perfect (lili73) 286 764
148) Must or Have to? (woodyrun) 286 740
149) The/an/nothing (bridg) 284 865
150) To be (anonyme) 283 292
151) Vocabulary: asking and answering (here4u) 280 422
152) Can and can't (laure95) 280 089
153) Modal verbs (bridg) 277 060
154) Some / Any / no... (bridg) 270 085
155) Days of the week (bridg) 269 027
156) So / neither (anonyme) 264 192
157) Past simple (video) (lucile83) 263 471
158) Used to (bridg) 260 205
159) Should / must (anonyme) 259 159
160) Past tense (anonyme) 259 067
161) Present continuous (chnawa) 258 970
162) Vocabulary: on the phone (here4u) 258 698
163) Find out a quantity (webmaster) 258 432
164) Superlative + and adjective (lucile83) 256 912
165) Articles : a / an / the / Ø (anonyme) 255 717
166) Comparative and superlative (anonyme) 254 312
167) Numbers 1/100 (anonyme) 253 295
168) Modal can (video) (lucile83) 252 661
169) Relatives pronouns (who, which, that...) (anonyme) 247 796
170) Comparatives (anonyme) 245 829
171) Vocabulary: at the restaurant (here4u) 245 632
172) A few, a little, few, little (anonyme) 244 894
173) Would rather / would prefer to (anonyme) 244 095
174) Present continuous and the Going to form (anonyme) 242 298
175) Have something done (anonyme) 239 626
176) Should/ have to/ must (anonyme) 239 517
177) The past (webmaster) 237 691
178) Future continuous and future perfect. (felin) 237 393
179) Used to/would (woodyrun) 237 159
180) How to ask a question in English (bridg) 234 983
181) I wish, if only (felin) 233 911
182) Pluperfect (webmaster) 233 661
183) Countable or Uncountable? (webmaster) 232 893
184) Some / any (younes91) 231 997
185) Should / shouldn't (anonyme) 231 113
186) Present simple or continuous (bridg) 230 765
187) Adjectives - ing and ed (felin) 228 634
188) Hypothesis (webmaster) 227 849
189) Auxiliary BE (lucile83) 226 224
190) Articles a/an/the/0 (bridg) 226 058
191) Article The or nothing (anonyme) 225 740
192) Present perfect with Ever - never - (anonyme) 225 334
193) Present continuous OR Present simple? (bridg) 225 198
194) Must or mustn't (laure95) 224 724
195) Simple Preterite OR Preterite (BE+ing) (webmaster) 222 646
196) To / in order to / so as to / so that (irish21) 219 610
197) Present perfect (bridg) 219 313
198) What time is it ? (anonyme) 217 447
199) Comparison (komiks) 217 235
200) Indirect speech (bridg) 215 983
