Another site:
AllYESTERDAY'S STATSTop 200 most popular tests to learn English...
1) 'Than', 'as' or '(that)? (here4u) 1 228
2) Present simple (webmaster) 475
3) Prepositions (anonyme) 220
4) Present continuous (webmaster) 216
5) Preterite (webmaster) 200
6) Passive form (lucile83) 190
7) Comparatives / Superlatives (webmaster) 177
8) Placement test : grammar for beginners (lucile83) 170
9) Present perfect (webmaster) 159
10) Present simple or continuous (lucile83) 150
11) A/AN (webmaster) 146
12) Preterite (webmaster) 143
13) 'Almost similar words' part 2 (here4u) 136
14) Present continuous (webmaster) 132
15) Greeting and meeting (anonyme) 132
16) Comparatives and Superlatives (anonyme) 122
17) Work environment (anonyme) 120
18) Past simple or present perfect (lucile83) 119
19) Present simple (webmaster) 115
20) THE/ A / AN / nothing (webmaster) 111
21) Present simple (komiks) 111
22) Present perfect simple (webmaster) 109
23) Modal verbs and use (anonyme) 105
24) What time is it? (webmaster) 102
25) Present continuous (chnawa) 100
26) Present perfect or past tense (anonyme) 97
27) So...That / Such...That (anonyme) 97
28) Test de niveau anglais (webmaster) 96
29) Superlatives (frapedur) 95
30) Present perfect simple (bridg) 93
31) Past simple or present perfect simple (anonyme) 93
32) Interrogative words (anonyme) 86
33) Tenses and verbs (anonyme) 85
34) There is / there are (bikette329) 83
35) Comparative and superlative (anonyme) 83
36) Simple past tense (anonyme) 82
37) Auxiliary BE (webmaster) 76
38) What time is it? (webmaster) 76
39) Present simple (lucile83) 73
40) Possessive Adjectives (anonyme) 72
41) Comparison (komiks) 71
42) Verbs and tenses (anonyme) 67
43) Past perfect (lili73) 65
44) Understand and choose (anonyme) 65
45) Could or Couldn't (anonyme) 65
46) Comparatives (anonyme) 63
47) Words (anonyme) 62
48) To be (bridg) 61
49) Much, many, little and few (felin) 59
50) Two presents: present continuous, present simple (webmaster) 58
51) Use of words (anonyme) 58
52) Basic but necessary words (anonyme) 56
53) Sport Test (anonyme) 55
54) Right words (anonyme) 55
55) Numbers (webmaster) 54
56) Modals (webmaster) 54
57) Present perfect continuous (anonyme) 54
58) Past simple or present perfect (lucile83) 52
59) Past simple, past continuous or Past perfect (anonyme) 51
60) Possessive adjectives (jagienka) 50
61) Possessive adjectives (anonyme) 50
62) Verbs and tenses (anonyme) 50
63) Preterite (webmaster) 49
64) Pronouns (woodyrun) 49
65) Can and can't (laure95) 49
66) Past simple (anonyme) 48
67) 2 Preterites (webmaster) 47
68) Present Simple, Present Continuous, Past Simple (anonyme) 47
69) The alphabet in English (webmaster) 46
70) Past simple or past continuous (lucile83) 46
71) Connecting words (anonyme) 46
72) Must or mustn't (laure95) 45
73) Trip to London and past tense (anonyme) 45
74) Present simple (lucile83) 44
75) Vocabulary - Placement test (bridg) 44
76) Understanding of sentences (anonyme) 44
77) Trade and words (anonyme) 44
78) Adverbs of frequency (lucile83) 43
79) Ask questions (chnawa) 41
80) Idioms (anonyme) 41
81) Capitals (anonyme) 41
82) Object pronouns (bridg) 40
83) Preterite continuous (BE + -ING) (webmaster) 39
84) Adjectives (antoniutti) 39
85) Tenses (anonyme) 39
86) Possessive adjectives and pronouns (woodyrun) 38
87) Adverbs of frequency (anonyme) 38
88) Adjectives (webmaster) 37
89) Simple present (bridg) 37
90) Adjectives (lucile83) 37
91) Short placement test (webmaster) 37
92) Words and comprehension (anonyme) 37
93) Riddles (anonyme) 37
94) Questions : how to ask them (lucile83) 36
95) Scramble Word (anonyme) 36
96) Placement test (beginners) (lili73) 36
97) Ask a question (anonyme) 36
98) Antonyms (anonyme) 36
99) Two presents: simple and continuous (webmaster) 35
100) Must or Have to? (woodyrun) 35
101) Tenses and verbs (anonyme) 35
102) Fruits - vocabulary (denis76) 35
103) Past Simple / Past Perfect / Past Perfect Continuous (greg100) 34
104) Verb tenses (anonyme) 34
105) There is / There are (anonyme) 34
106) Former - latter/First - last (anonyme) 34
107) Verb Agreement (anonyme) 34
108) Simple past or present perfect (anonyme) 34
109) To be (bridg) 33
110) Present Simple (anuesther) 33
111) Past simple tense (woodyrun) 33
112) List of 200 irregular verbs and audio (bridg) 33
113) English-speaking country excursion (anonyme) 33
114) Rainy weather (anonyme) 33
115) Past and time clauses (anonyme) 32
116) Tenses and verbs (anonyme) 32
117) Superlative (anonyme) 32
118) Present perfect (anonyme) 32
119) 'Almost similar words': part 1. (here4u) 32
120) Family life (bridg) 31
121) Countries & nationalities (bridg) 31
122) Past tenses (bridg) 31
123) Family (bridg) 31
124) Relative pronouns (anonyme) 31
125) Verbs and tenses (anonyme) 31
126) To be and tenses (anonyme) 31
127) Present simple (anonyme) 31
128) The/an/nothing (bridg) 30
129) Order of adjectives (webmaster) 30
130) Comparative of superiority (lucile83) 30
131) Conditional clauses (lucile83) 30
132) Input correct form of verb. (anonyme) 30
133) Present simple or continuous (anonyme) 30
134) Adjectives - ed - ing (anonyme) 30
135) Comparative or Superlative (anonyme) 30
136) CAN / MUST (webmaster) 29
137) Spelled words N°1 (bridg) 29
138) Weather and Climate (anonyme) 29
139) Contrasting Ideas (anonyme) 29
140) Past simple (anonyme) 29
141) Past perfect or past simple (anonyme) 29
142) Correct form of the verbs (anonyme) 29
143) Prepositions In, On and At (anonyme) 29
144) Present Simple or Continuous or Gerund (anonyme) 29
145) There is and there are (tinou) 28
146) Past simple tense (anonyme) 28
147) May/might (anonyme) 28
148) Preterite: simple or continuous? (webmaster) 27
149) Genitive (webmaster) 27
150) A/an/Ø (bridg) 27
151) TLE : To have (lucile83) 27
152) Tenses and verbs (anonyme) 27
153) Present simple and continuous (anonyme) 27
154) Simple past or Present perfect (anonyme) 27
155) July 4th Barbecue (anonyme) 27
156) Do - don't - does - doesn't (anuesther) 27
157) Family (anonyme) 27
158) To be - Present (bridg) 26
159) Plural (webmaster) 26
160) How to ask a question in English (bridg) 26
161) Narration tenses (mylaw) 26
162) Present perfect or past simple (anonyme) 26
163) AT - ON - IN Time clauses (bernard02) 26
164) Verbs in the Past Tense (anonyme) 26
165) Present simple or continuous (anonyme) 26
166) Tenses of the verbs (anonyme) 26
167) Work out (anonyme) 26
168) Tenses of verbs (anonyme) 26
169) Modal verbs (felin) 25
170) Some / any (younes91) 25
171) Can / could/ may/ might (woodyrun) 25
172) Future with When,As soon as... (anonyme) 25
173) Past simple (anonyme) 25
174) Superlative (lili73) 25
175) To / in order to / so as to / so that (irish21) 25
176) Past simple (anonyme) 25
177) Tenses and verbs (anonyme) 25
178) Possessive adjectives (anonyme) 25
179) Numbers > 100 (webmaster) 24
180) Modals (webmaster) 24
181) I wish, if only (felin) 24
182) Nationalities (webmaster) 24
183) Should or shouldn't ? (laure95) 24
184) Future after when (lili73) 24
185) Family tree (anonyme) 24
186) Direct and indirect speech (lili73) 24
187) Answering questions (anonyme) 24
188) Passive voice (komiks) 24
189) Verbs and conjugation (anonyme) 24
190) Plural of nouns (anonyme) 24
191) Who or Whom (anonyme) 24
192) Word search (anonyme) 24
193) Used to - Be Used to - Get used to (anonyme) 24
194) Present Simple vs. Past Simple (anonyme) 24
195) Can, can't, must OR mustn't (colchique) 23
196) Present perfect simple or continuous (jagienka) 23
197) Adverbs of frequency (lucile83) 23
198) Active and passive form (anonyme) 23
199) Relative pronouns (laure95) 23
200) Past simple (anonyme) 23
