Another site:
AllTop 200 most popular tests to learn English...
1) Test de niveau anglais (webmaster) 6 773 275
2) Placement test : grammar for beginners (lucile83) 5 983 686
3) A/AN (webmaster) 5 359 800
4) Auxiliary BE (webmaster) 3 221 632
5) Present continuous (webmaster) 2 995 829
6) Present simple (webmaster) 2 904 041
7) Present simple (webmaster) 2 594 283
8) Present continuous (webmaster) 2 427 722
9) Adjectives (webmaster) 2 091 886
10) A/an (anonyme) 2 012 329
11) Present perfect simple (webmaster) 1 637 779
12) Preterite (webmaster) 1 619 881
13) Vocabulary - Placement test (bridg) 1 617 944
14) Preterite (webmaster) 1 442 454
15) Short placement test (webmaster) 1 442 192
16) To be (bridg) 1 404 479
17) What time is it? (webmaster) 1 347 598
18) Present perfect (webmaster) 1 341 569
19) The alphabet in English (webmaster) 1 319 478
20) Adjectives (lucile83) 1 214 239
21) What time is it? (webmaster) 1 205 398
22) Numbers (webmaster) 1 187 672
23) 'A' ou 'An' (anonyme) 1 173 114
24) Two presents: present continuous, present simple (webmaster) 1 147 200
25) To be (bridg) 1 144 159
26) Comparatives / Superlatives (webmaster) 1 098 843
27) Numbers (webmaster) 1 069 196
28) CAN / MUST (webmaster) 1 057 480
29) THE/ A / AN / nothing (webmaster) 1 030 768
30) Comparatives (webmaster) 1 006 147
31) Family life (bridg) 999 347
32) Numbers > 100 (webmaster) 985 435
33) Future (going to/will/present continuous) (anonyme) 961 681
34) Plural (webmaster) 954 523
35) Superlatives (webmaster) 873 882
36) Adjectives (anonyme) 873 533
37) Simple present (bridg) 852 517
38) Spelled words N°1 (bridg) 848 919
39) Placement test beginners: Check your spelling (lucile83) 829 554
40) Introducing oneself (webmaster) 826 444
41) Adverbs of frequency (lucile83) 815 291
42) Family (bridg) 783 567
43) General test-End of high school / Beginning of university (webmaster) 781 810
44) Present simple (lucile83) 778 080
45) Frequency adverbs (webmaster) 776 786
46) Present BE + Ving (bridg) 763 618
47) Genitive (webmaster) 722 725
48) Family tree (anonyme) 718 418
49) Preterite: simple or continuous? (webmaster) 715 053
50) Passive form (lucile83) 713 962
51) Placement test (beginners) (lili73) 699 898
52) Past simple or present perfect (lucile83) 691 507
53) Future (webmaster) 675 210
54) 2 Preterites (webmaster) 660 636
55) Present perfect simple (bridg) 657 683
56) Preterite (webmaster) 618 531
57) List of 200 irregular verbs and audio (bridg) 614 863
58) Modals (webmaster) 612 007
59) Spelled words N°2 (bridg) 608 267
60) Height (webmaster) 605 692
61) Modals (webmaster) 603 288
62) Articles a / an / the (lucile83) 596 722
63) Plural forms (bridg) 576 389
64) Nationalities (webmaster) 573 451
65) Past continuous / Past simple (anonyme) 562 747
66) Irregular plurals (bridg) 552 634
67) Two presents: simple and continuous (webmaster) 548 873
68) Preterite (bridg) 548 014
69) Vocabulary: greeting people (here4u) 536 392
70) Superlatives (frapedur) 535 166
71) Give your opinion (bridg) 531 076
72) Adverbs of Frequency (bridg) 516 298
73) Present simple or continuous (lucile83) 508 257
74) Present perfect / preterite ? (anonyme) 506 699
75) Possessive case (anonyme) 479 770
76) Countries & nationalities (bridg) 472 553
77) 'The' or nothing? (webmaster) 470 624
78) Introducing oneself (easy) (webmaster) 470 212
79) Past tenses (bridg) 469 725
80) Passive voice (webmaster) 461 693
81) Present Simple vs. Past Simple (anonyme) 455 085
82) Questions : how to ask them (lucile83) 447 482
83) General Test II / End of high school / Beginning of universi (webmaster) 445 566
84) IN, ON, AT or TO? (webmaster) 444 272
85) Relative pronouns (webmaster) 443 259
86) Comparative of superiority (lucile83) 436 879
87) How to pronounce the final -ED? (past simple) (webmaster) 436 111
88) Relative clauses (webmaster) 422 540
89) Sounds: [h] (webmaster) 419 040
90) Comparative (anonyme) 412 131
91) A/an/Ø (bridg) 397 682
92) Future simple (lucile83) 395 068
93) Past simple (anonyme) 393 448
94) This / That / These / Those (webmaster) 391 973
95) Conditional (webmaster) 390 883
96) Passive voice (anonyme) 389 546
97) Comparing (webmaster) 387 577
98) Can / could/ may/ might (woodyrun) 378 711
99) Present perfect or past tense (anonyme) 375 923
100) Much, many, little and few (felin) 371 242
101) Personal pronouns (anonyme) 371 072
102) Some, any, no, enough, too/too much/too many (webmaster) 367 723
103) Preterite continuous (BE + -ING) (webmaster) 367 683
104) Genitive case (bridg) 367 148
105) Confusing words - Placement test (bridg) 364 317
106) Irregular verbs (webmaster) 362 869
107) Numbers from 1 to 10 (lucile83) 361 038
108) Past perfect simple, past perfect continuous (anonyme) 360 615
109) Present continuous or present simple (webmaster) 359 142
110) Present perfect or preterite? (anonyme) 355 150
111) Simple Past : regular verbs (anonyme) 351 806
112) Comparative Adjectives (bridg) 351 785
113) Who, Whom, Which, or Whose? (anonyme) 348 076
114) Past simple (video) (lucile83) 347 140
115) Past simple or past continuous (lucile83) 340 032
116) While / When (anonyme) 337 249
117) What time is it? (webmaster) 337 150
118) Modals (tinou) 336 035
119) Modal: may/might (lucile83) 333 744
120) Cardinal and ordinal numbers (anonyme) 328 177
121) Possessive adjectives and pronouns (woodyrun) 323 539
122) The superlative (anonyme) 323 192
123) How to talk about the weather (lili73) 320 835
124) Since and for (lucile83) 318 029
125) Flags (webmaster) 317 060
126) Irregular verbs (bridg) 315 448
127) Prepositions - in, on, at (anonyme) 313 778
128) Pronouns (woodyrun) 312 249
129) Tenses (anonyme) 311 055
130) Placement test 3 (webmaster) 310 007
131) Order of adjectives (webmaster) 306 111
132) Could/Couldn't (laure95) 305 463
133) Comparative (anonyme) 303 948
134) Adjectives and prepositions (lucile83) 303 800
135) Agreement Tags (webmaster) 303 601
136) Asking questions (webmaster) 302 670
137) Present perfect OR simple past? (bridg) 297 970
138) Questions in the past tense (lucile83) 296 980
139) Superlative Adjectives (bridg) 295 189
140) Uncountable nouns (webmaster) 295 085
141) Object pronouns (bridg) 293 855
142) Placement test 1 (lucile83) 292 249
143) Present simple (lucile83) 290 002
144) Prefer/rather (bridg) 288 796
145) Passive form (anonyme) 288 621
146) Can/Must/Should (laure95) 288 467
147) Must or Have to? (woodyrun) 286 455
148) Past perfect (lili73) 285 838
149) The/an/nothing (bridg) 284 654
150) To be (anonyme) 283 168
151) Vocabulary: asking and answering (here4u) 280 400
152) Can and can't (laure95) 279 446
153) Modal verbs (bridg) 276 929
154) Some / Any / no... (bridg) 269 915
155) Days of the week (bridg) 268 972
156) So / neither (anonyme) 264 053
157) Past simple (video) (lucile83) 263 298
158) Used to (bridg) 260 104
159) Should / must (anonyme) 258 968
160) Past tense (anonyme) 258 879
161) Vocabulary: on the phone (here4u) 258 670
162) Find out a quantity (webmaster) 258 371
163) Present continuous (chnawa) 257 936
164) Superlative + and adjective (lucile83) 256 676
165) Articles : a / an / the / Ø (anonyme) 255 020
166) Comparative and superlative (anonyme) 253 736
167) Numbers 1/100 (anonyme) 253 115
168) Modal can (video) (lucile83) 252 533
169) Relatives pronouns (who, which, that...) (anonyme) 247 774
170) Vocabulary: at the restaurant (here4u) 245 605
171) A few, a little, few, little (anonyme) 244 678
172) Comparatives (anonyme) 244 228
173) Would rather / would prefer to (anonyme) 243 969
174) Present continuous and the Going to form (anonyme) 242 190
175) Have something done (anonyme) 239 518
176) Should/ have to/ must (anonyme) 238 968
177) The past (webmaster) 237 615
178) Future continuous and future perfect. (felin) 237 305
179) Used to/would (woodyrun) 236 801
180) How to ask a question in English (bridg) 234 772
181) I wish, if only (felin) 233 819
182) Pluperfect (webmaster) 233 551
183) Countable or Uncountable? (webmaster) 232 784
184) Some / any (younes91) 231 377
185) Should / shouldn't (anonyme) 230 967
186) Present simple or continuous (bridg) 230 764
187) Adjectives - ing and ed (felin) 228 481
188) Hypothesis (webmaster) 227 692
189) Auxiliary BE (lucile83) 226 122
190) Articles a/an/the/0 (bridg) 225 924
191) Article The or nothing (anonyme) 225 549
192) Present perfect with Ever - never - (anonyme) 225 229
193) Present continuous OR Present simple? (bridg) 225 042
194) Must or mustn't (laure95) 224 249
195) Simple Preterite OR Preterite (BE+ing) (webmaster) 222 541
196) To / in order to / so as to / so that (irish21) 219 372
197) Present perfect (bridg) 219 126
198) What time is it ? (anonyme) 217 343
199) Comparison (komiks) 216 549
200) Indirect speech (bridg) 215 738
