Again, "bugs in writing"

Full versus incomplete infinities
You should use full infinitives in a series in which the infinitives are modified in different ways. That is, to write well, or to avoid mistakes,...

Contraction
You should not use contractions in formal writing; it's ok to use them in casual writing

Per
You should use per in formal writing rather than "a"

Fuzzy words
very: exceptionally, remarkably
a lot of: myriad, multifarious, multitudinous

Data
You should use "data" only to denote numerous discrete measurements. When you wish to refer to a single item, use "datum".

Ensure, assure, insure
You should use each word correctly to "ensure" that your readers are "assured" that you know
what you are doing, so that they feel no need to "insure" themselves against damage from bad
prose.

Above and below
You should use words such as previous, preceding, and earlier, rather than above. And you should use words such as following, next, and here, rather than below

Who versus that
You should use "who" to denote creatures to whom you grant human characteristics, and should use "that" for every other object that you discuss

Though
You should not use "though" on its own, you should use "although" or "even though"

With terms
You should "meet" people, rather than "meething with" them
You should "visit" people, rather than "visiting with" them
You should "consult" people, rather than "consuting with" them
You should place objects or people "with" each other, rather than "together with" each other
You should avoid using "along with" to mean "as well as" or simply "with"

Adverbs
Unless you have an excellent reason to do otherwise, you should place adverbs at the ends of the phrases to which they belong

Inference and deduction
The words "deduce" and "infer" have usefully different meanings that allow you to distinguish
the direction of reasoning. "Deduction" is reasoning from the general to the specific, or from the population to the individual. "Inference" is reasoning from the specific to the general, or from the sample to the population. Be careful not to confuse "infer" with "imply", which means to indicate or express indirectly.

Whether vs. if
In most cases, you should use simply "whether", rather than "whether or not". Use "whether or not" when you mean "regardless" or "irrespective". Keep intact the phrase "whether or not"; do not spread it out over your sentence.
You should use "if" when you are simply placing a constraint

Comprise
You should never use "is comprised of"

In order to
The phrase "in order to" is fusty and verbose; in almost all situations, "to" will suffice, and "so as to" rather than "in order to"

Persons vs. people
You should almost never use "persons"; you should use "people" when you intend to denote the plural of "person"

Last
You should use "preceding", "previous", "foregoing", or a similar word, or use "final", "concluding", "closing", "terminal", "endmost" if that is what you mean

Focus (on)
use concentrate on, obsessed with, pay attention to, rather than the worn-out "focus"

Around
There are sufficient serviceable words that mean "approximately", "more or less", "about", "roughly", "generally", and "in round numbers"; you should not drag "around" into service for this purpose

Semicolon
You should use a semicolon when what follows constitutes a complete sentence
You should use a semicolon before complete-sentence clauses that begin with "for example" and "that is"

Tense
When you describe research results, you should generally use the past tense to indicate that the results apply only to the population studied. If you want to imply that the results generalize, then you can use the present tense.

Abstract
In an abstract for a research paper, you should state
What the problem was
what your hypothesis was
how you tested it
what the results were
what your conclusions are

Importantly
It is important that you not use "importantly" when you mean "important", which is arrogant, or you can write important material

Since
You should reserver "since" for time relationships, and should use "because" to indicate causal linkages, because those are the correct uses of the words

Note that
When you wish to flag a sentence for your readers' attention, you should first ask yourself whether the content is not sufficient to call attention to itself without your aid; if you determine that the sentence needs a flashing light, use the simplest choice: "not that", rather than "notice that" or "it is important to notice that"

Maybe vs. may be
You should set the term "maybe", meaning "perhaps", as one word; you should set the verb "may be" as two words

Continuous vs. continual
"Continuous" means "occurring without interruption", while "continual" means "recurring steadily"

Italics
You should use italics for emphasis rather than boldface,