1 6.18% the 6.18
2 4.23% is, was, be, are, 's (is), were, been, being, 're, 'm, am 10.41
3 2.94% of 13.35
4 2.68% and 16.03
5 2.43% a, an 18.49
6 1.80% in, inside (preposition) 20.29
7 1.62% to (infinitive verb marker) * 21.29
8 1.37% have, has, have, 've, 's (has), had, having, 'd (had) 23.28
9 1.27% he, him, his 24.55
10 1.25% it, its 25.80
11 1.17% I, me, my 26.27
12 0.91% to (preposition) * 27.88
13 0.86% they, them, their 28.74
14 0.86% not, n't, no (interjection) 29.60
15 0.83% for 30.43
16 0.83% you, your 31.26
17 0.70% she, her 31.96
18 0.65% with 32.61
19 0.64% on 33.25
20 0.62% that (conjunction) * 33.87
21 0.58% this, these 34.45
22 0.57% that (demonstrative),* those 35.02
23 0.55% do, did, does, done, doing 35.57
24 0.51% we, us, our 36.08
25 0.50% by 36.58
26 0.47% at 37.05
27 0.45% but (conjunction) 37.50
28 0.44% 's (possessive) 37.94
29 0.41% from 38.35
30 0.40% as (many parts of speech) 38.75
31 0.37% wich 39.12
32 0.37% or 39.49
33 0.31% will, 'll 39.80
34 0.28% said, say, says, saying 40.08
35 0.25% would 40.33
36 0.25 what 40.58
37 0.23% there (existential, in "there is ..." phrases) * 40.81
38 0.23% if 41.04
39 0.23% can - be able to ; may 41.27
40 0.22% all 41.49
41 0.22% who, whose 41.71
42 0.21% so (adverb / conjunction) 41.92
43 0.20% go, went, gone, goes 42.12
44 0.20% more 42.32
45 0.19% other, another 42.51
46 0.19% one (numeral) 42.70
47 0.18% see, saw, seen, seeing 42.88
48 0.18% know, knew, known, knows, knowing - have knowledge of 43.06
49 0.18% up 43.24
50 0.17% some 43.41

The items listed above make up over 43% of the body of English. Note that all but two words are included in Basic English. This gives why Basic is so clear and able to say things in a way common to those who make use of English everyday.

Note : "to", "that" and other words are separated by senses. If combined as one word, they would rank higher.

 

A useful list of the 1,000 most common words in the English Language can be found HERE.

 

Finally, Michael P. West provides in his book "A General Service List of English Words" (Longman, London, 1953) a list of 2,284 useful words. The Longman Defining Vocabulary for intermediate students is based on this list, which makes Longman's books useful for advanced Basic English learners.