As a rule of thumb, the use of double negatives (e.g., not + nobody and never) is grammatically incorrect. However, multiple negative words are sometimes used inadvertently in a sentence. This may impede the clarity since the readers have to grasp the technical topics, along with deciphering unnecessary negative terminologies. Here are some proofreading tips in this regard:
Strengthen negatives
“Not” is considered a weak word in writing. You can avoid the word “not” using three ways:
Substitute negatives
“No, none, and never” are considered strong negatives, which can be replaced with “not”. Moreover, it should be noted that beginning a sentence with a negative is powerful.
There was not any X. No X existed/appeared.
Not one patient survived. None of the patients survived.
They had not seen X before. Never had they seen it before.
Substitute negative prefixes
“Not” can be also replaced by the proper negative prefixes, such as un, in, in, non, etc.
The cause is not known. The cause is unknown.
The text was not coherent. The text was incoherent.
The task was not possible. The task was impossible.
The results were not significant. The results were non-significant.
This drug is not made anymore. This drug has been discontinued.
Change to negative verbs or use negative adjectives
Sometimes, you can substitute “not” with a proper negative verb or adjective, such as fail, lack, etc.
The plan did not work. The plan failed (to succeed).
The solution didn’t have X. The solution lacked X.
X was not in the samples. In the samples, X was absent.
Controls didn’t have enough X. Controls had insufficient X.
The test was not finished. The test was incomplete.
There are also other points that should be taken into account when using negatives:
Do not use phrases containing “no/not“, particularly when referring to quantity.
Change the negative phrase into a positive one.
No fewer than → at least
No more than → at most
Do not use no/not+ until
You can replace it with only.
No research has investigated this issue until recently. → Research on this issue only began recently.
Do not use not + but for
You can replace it with only.
They did not seek the whole concept but its elements. → They only sought the elements of the concept.