“BE” NOT

Notice that some of the forms of BE, such as, “were” are more frequent in the iWeb corpus than the present forms.  Also, notice that “is not” is much more common than “I am.”  Having said all this, remember these are only two slot Ngrams which means there may be other grammar forms connected with them.  For example “is not” might be “is not going to be” or “is not done.” that means we cannot say that this frequency is of present simple only.  What we do know is that practising these two words together is extremely common and therefore useful for learners to practise often.

The most common “is not” collocates (4 spaces either side) most frequently with the 10 following words on the COCA corpus:

1 CLEAR 3198
2 EASY 2231
3 SURPRISING 2210
4 NECESSARILY 2075
5 MERELY 915
6 UNUSUAL 858
7 UNCOMMON 839
8 ENTIRELY 734
9 SUFFICIENT 658
10 RETAINED 504

“is not clear” collocates (4 spaces either side) on the iWeb corpus:

1 IT 22368
2 WHETHER 4675
3 HOW 3327
4 WHY 1448
5 ALTHOUGH 661
6 EXACTLY 487
7 EXTENT 179
8 DIAGNOSIS 53
9 MECHANISM 52
10 PRECISELY 40

“It is not clear whether” collocates (4 spaces to the right) on the iWeb:

1 THESE 201
2 ACTUALLY 51
3 TRUMP 18
4 REFERS 17
5 BENEFIT 16