Subject-verb disagreements:

The subject of a sentence is the noun that performs the action described in the sentence. If the subject is singular and the verb is plural, the subject and verb of that sentence are in disagreement. The rules of English grammar dictate that the subject and verb must agree with each other in number, i.e., they both should either be singular or plural. - Singular subjects should have singular verbs
e.g.: The table is red.
- Plural subjects should have plural verbs.
e.g.: The tables are red.

Missing introductory commas

In sentences that begin with an introductory phrase, word, or clause, use a comma to separate the introductory text from the rest of the sentence. This comma is called the introductory comma and it tells the reader to pause slightly. E.g. However, Jim had left by then.
Or
In this study, we were unable to include red blood cells.

Nominalization of verbs

Nominalization is the use of parts of speech that are not nouns, such as verbs, as nouns. Some authors tend to overuse nominalized verbs and make their writing stodgy and wordy. Such nominalized verbs are also called smothered verbs. They weaken the quality of writing.
In the example given below, the verb “discuss” is used as a noun. This makes the sentence unnecessary lengthy.
Incorrect: We had a discussion about the issue. Omitting the weak smothered verb and using the verb in its original form makes the sentence terse and crisp. It also increases the impact of the sentence. Such a style is preferred in academic writing.
Correct: We discussed the issue.

Use of the adverb “respectively”

The adverb respectively means “in the order given”. In sentences that attribute one list of items to corresponding items on another list, the term “respectively” can be used for clarity and conciseness. Original sentence: Jim is 8 years old, John is 9 years old, and Joe is 10 years old.
(This sentence, although grammatically correct, is long and repetitive.)
Concise form: Jim, John, and Joe are 8, 9, and 10 years old, respectively.
(This sentence construction is concise and eloquent.)

Lack of parallelism

Parallelism, also known as parallel structure, is achieved when grammatically similar components or phrases and clauses with similar grammatical structure are used in a sentence. It is used to balance nouns with nouns, verbs with verbs, clauses with clauses, and so on.
Parallel structure enhances the clarity of the text and makes the text easy to read. Incorrect: Tina likes reading, painting, and to cook.
Correct: Tina likes reading and cooking.
Or
Tina likes to read, paint, and cook.