Another site:
AllTop 200 most popular tests to learn English...
1) Test de niveau anglais (webmaster) 6 775 151
2) Placement test : grammar for beginners (lucile83) 5 986 596
3) A/AN (webmaster) 5 361 874
4) Auxiliary BE (webmaster) 3 222 631
5) Present continuous (webmaster) 2 997 067
6) Present simple (webmaster) 2 907 772
7) Present simple (webmaster) 2 595 486
8) Present continuous (webmaster) 2 429 977
9) Adjectives (webmaster) 2 092 564
10) A/an (anonyme) 2 013 464
11) Present perfect simple (webmaster) 1 639 620
12) Preterite (webmaster) 1 622 688
13) Vocabulary - Placement test (bridg) 1 618 391
14) Preterite (webmaster) 1 444 275
15) Short placement test (webmaster) 1 442 741
16) To be (bridg) 1 405 180
17) What time is it? (webmaster) 1 348 193
18) Present perfect (webmaster) 1 343 184
19) The alphabet in English (webmaster) 1 320 100
20) Adjectives (lucile83) 1 214 944
21) What time is it? (webmaster) 1 206 431
22) Numbers (webmaster) 1 188 031
23) 'A' ou 'An' (anonyme) 1 174 060
24) Two presents: present continuous, present simple (webmaster) 1 148 114
25) To be (bridg) 1 144 712
26) Comparatives / Superlatives (webmaster) 1 100 559
27) Numbers (webmaster) 1 069 784
28) CAN / MUST (webmaster) 1 057 859
29) THE/ A / AN / nothing (webmaster) 1 031 938
30) Comparatives (webmaster) 1 006 518
31) Family life (bridg) 999 949
32) Numbers > 100 (webmaster) 985 820
33) Future (going to/will/present continuous) (anonyme) 962 290
34) Plural (webmaster) 955 035
35) Superlatives (webmaster) 874 274
36) Adjectives (anonyme) 874 054
37) Simple present (bridg) 853 016
38) Spelled words N°1 (bridg) 849 474
39) Placement test beginners: Check your spelling (lucile83) 829 726
40) Introducing oneself (webmaster) 826 744
41) Adverbs of frequency (lucile83) 816 044
42) Family (bridg) 784 029
43) General test-End of high school / Beginning of university (webmaster) 782 137
44) Present simple (lucile83) 778 780
45) Frequency adverbs (webmaster) 777 222
46) Present BE + Ving (bridg) 764 153
47) Genitive (webmaster) 723 023
48) Family tree (anonyme) 718 850
49) Passive form (lucile83) 716 763
50) Preterite: simple or continuous? (webmaster) 715 568
51) Placement test (beginners) (lili73) 700 296
52) Past simple or present perfect (lucile83) 692 444
53) Future (webmaster) 675 434
54) 2 Preterites (webmaster) 661 101
55) Present perfect simple (bridg) 658 759
56) Preterite (webmaster) 619 306
57) List of 200 irregular verbs and audio (bridg) 615 354
58) Modals (webmaster) 612 262
59) Spelled words N°2 (bridg) 608 674
60) Height (webmaster) 605 978
61) Modals (webmaster) 604 080
62) Articles a / an / the (lucile83) 596 738
63) Plural forms (bridg) 576 812
64) Nationalities (webmaster) 573 805
65) Past continuous / Past simple (anonyme) 564 260
66) Irregular plurals (bridg) 553 040
67) Two presents: simple and continuous (webmaster) 549 064
68) Preterite (bridg) 548 330
69) Vocabulary: greeting people (here4u) 536 433
70) Superlatives (frapedur) 536 418
71) Give your opinion (bridg) 531 438
72) Adverbs of Frequency (bridg) 516 543
73) Present simple or continuous (lucile83) 509 231
74) Present perfect / preterite ? (anonyme) 507 567
75) Possessive case (anonyme) 480 136
76) Countries & nationalities (bridg) 472 907
77) 'The' or nothing? (webmaster) 470 896
78) Introducing oneself (easy) (webmaster) 470 408
79) Past tenses (bridg) 470 107
80) Passive voice (webmaster) 462 185
81) Present Simple vs. Past Simple (anonyme) 455 667
82) Questions : how to ask them (lucile83) 447 763
83) General Test II / End of high school / Beginning of universi (webmaster) 445 788
84) IN, ON, AT or TO? (webmaster) 444 536
85) Relative pronouns (webmaster) 443 662
86) Comparative of superiority (lucile83) 437 327
87) How to pronounce the final -ED? (past simple) (webmaster) 436 516
88) Relative clauses (webmaster) 422 778
89) Sounds: [h] (webmaster) 419 225
90) Comparative (anonyme) 412 571
91) A/an/Ø (bridg) 398 105
92) Future simple (lucile83) 395 538
93) Past simple (anonyme) 394 953
94) This / That / These / Those (webmaster) 392 187
95) Conditional (webmaster) 391 153
96) Passive voice (anonyme) 389 876
97) Comparing (webmaster) 387 730
98) Can / could/ may/ might (woodyrun) 378 938
99) Present perfect or past tense (anonyme) 376 398
100) Much, many, little and few (felin) 371 774
101) Personal pronouns (anonyme) 371 141
102) Preterite continuous (BE + -ING) (webmaster) 368 183
103) Some, any, no, enough, too/too much/too many (webmaster) 367 845
104) Genitive case (bridg) 367 439
105) Confusing words - Placement test (bridg) 364 393
106) Irregular verbs (webmaster) 363 102
107) Numbers from 1 to 10 (lucile83) 361 237
108) Past perfect simple, past perfect continuous (anonyme) 360 681
109) Present continuous or present simple (webmaster) 359 309
110) Present perfect or preterite? (anonyme) 355 828
111) Simple Past : regular verbs (anonyme) 352 141
112) Comparative Adjectives (bridg) 351 918
113) Who, Whom, Which, or Whose? (anonyme) 348 333
114) Past simple (video) (lucile83) 347 595
115) Past simple or past continuous (lucile83) 340 850
116) While / When (anonyme) 337 746
117) What time is it? (webmaster) 337 397
118) Modals (tinou) 336 223
119) Modal: may/might (lucile83) 333 884
120) Cardinal and ordinal numbers (anonyme) 328 421
121) The superlative (anonyme) 323 952
122) Possessive adjectives and pronouns (woodyrun) 323 784
123) How to talk about the weather (lili73) 320 848
124) Since and for (lucile83) 318 223
125) Flags (webmaster) 317 253
126) Irregular verbs (bridg) 315 610
127) Prepositions - in, on, at (anonyme) 313 881
128) Pronouns (woodyrun) 312 693
129) Tenses (anonyme) 311 372
130) Placement test 3 (webmaster) 310 163
131) Order of adjectives (webmaster) 306 301
132) Could/Couldn't (laure95) 305 579
133) Comparative (anonyme) 304 102
134) Adjectives and prepositions (lucile83) 303 867
135) Agreement Tags (webmaster) 303 786
136) Asking questions (webmaster) 302 840
137) Present perfect OR simple past? (bridg) 298 084
138) Questions in the past tense (lucile83) 297 132
139) Superlative Adjectives (bridg) 295 441
140) Uncountable nouns (webmaster) 295 275
141) Object pronouns (bridg) 294 157
142) Placement test 1 (lucile83) 292 424
143) Present simple (lucile83) 290 436
144) Passive form (anonyme) 289 393
145) Prefer/rather (bridg) 289 001
146) Can/Must/Should (laure95) 288 625
147) Must or Have to? (woodyrun) 286 707
148) Past perfect (lili73) 286 617
149) The/an/nothing (bridg) 284 839
150) To be (anonyme) 283 287
151) Vocabulary: asking and answering (here4u) 280 418
152) Can and can't (laure95) 279 991
153) Modal verbs (bridg) 277 049
154) Some / Any / no... (bridg) 270 075
155) Days of the week (bridg) 269 022
156) So / neither (anonyme) 264 165
157) Past simple (video) (lucile83) 263 447
158) Used to (bridg) 260 201
159) Should / must (anonyme) 259 134
160) Past tense (anonyme) 259 045
161) Present continuous (chnawa) 258 825
162) Vocabulary: on the phone (here4u) 258 697
163) Find out a quantity (webmaster) 258 421
164) Superlative + and adjective (lucile83) 256 889
165) Articles : a / an / the / Ø (anonyme) 255 640
166) Comparative and superlative (anonyme) 254 231
167) Numbers 1/100 (anonyme) 253 267
168) Modal can (video) (lucile83) 252 656
169) Relatives pronouns (who, which, that...) (anonyme) 247 790
170) Vocabulary: at the restaurant (here4u) 245 628
171) Comparatives (anonyme) 245 627
172) A few, a little, few, little (anonyme) 244 868
173) Would rather / would prefer to (anonyme) 244 075
174) Present continuous and the Going to form (anonyme) 242 286
175) Have something done (anonyme) 239 597
176) Should/ have to/ must (anonyme) 239 452
177) The past (webmaster) 237 684
178) Future continuous and future perfect. (felin) 237 378
179) Used to/would (woodyrun) 237 106
180) How to ask a question in English (bridg) 234 962
181) I wish, if only (felin) 233 905
182) Pluperfect (webmaster) 233 645
183) Countable or Uncountable? (webmaster) 232 879
184) Some / any (younes91) 231 902
185) Should / shouldn't (anonyme) 231 100
186) Present simple or continuous (bridg) 230 765
187) Adjectives - ing and ed (felin) 228 620
188) Hypothesis (webmaster) 227 832
189) Auxiliary BE (lucile83) 226 217
190) Articles a/an/the/0 (bridg) 226 030
191) Article The or nothing (anonyme) 225 713
192) Present perfect with Ever - never - (anonyme) 225 329
193) Present continuous OR Present simple? (bridg) 225 173
194) Must or mustn't (laure95) 224 605
195) Simple Preterite OR Preterite (BE+ing) (webmaster) 222 636
196) To / in order to / so as to / so that (irish21) 219 588
197) Present perfect (bridg) 219 303
198) What time is it ? (anonyme) 217 437
199) Comparison (komiks) 217 127
200) Indirect speech (bridg) 215 955
