Check My Essay for Grammar

Subject-verb agreement is consistently among the most frequent grammar errors identified in academic writing research. A 2024 study from Heliyon lists it as one of the top errors among undergraduate writers. The error occurs when the grammatical number of the verb does not match the subject — complicated further in academic writing by collective nouns, inverted sentences, and quantifying phrases.

The subject is “results” (plural), not “experiment” (singular). The prepositional phrase between subject and verb creates the error.

Tense consistency is a defining marker of professional academic writing. Paperpal’s academic writing guide (2024) identifies tense inconsistency as one of the seven most common writing mistakes in research papers. The rule — past tense for methods and findings, present tense for established facts and discussion — is violated constantly in student drafts.

Methods use past tense (completed actions); findings interpreted in the discussion use present tense (current implications).

A comma splice joins two independent clauses with only a comma — no coordinating conjunction and no semicolon. Run-on sentences string multiple independent clauses without any separation. Both errors are flagged as readability failures by academic editors and account for a significant share of the 28% readability errors identified by Paperpal’s analysis of 2,674 academic papers.

A dangling modifier has no clear subject to attach to; a misplaced modifier is too far from the word it modifies. Both create unintended meanings that confuse academic readers. These errors are especially frequent in methodology sections where passive constructions dominate and the agent of the action is often omitted.

The original implies the results reviewed themselves. The subject after the introductory phrase must be the agent performing the action.

Article errors are the single most common grammar issue for ESL academic writers, and they remain among the hardest for even advanced non-native speakers to self-correct. The rules governing definite vs. indefinite articles and article omission with uncountable, plural, and proper nouns require deep familiarity with English usage patterns that automated grammar checkers frequently mishandle in academic contexts.

“Data” here is uncountable and non-specific, requiring no article. “A qualitative approach” is correct — indefinite, first mention.

Parallel structure requires that grammatically equivalent elements in a series, comparison, or listing use the same grammatical form. Faulty parallelism disrupts readability and creates a jarring inconsistency in sentence rhythm — particularly common in essay introductions, literature review summaries, and research objective statements.

Ambiguous pronoun reference occurs when a pronoun could refer to more than one antecedent, forcing the reader to guess the intended meaning. In academic writing where precise attribution of research findings and arguments is essential, pronoun ambiguity undermines the credibility of the analysis. Our editors identify and resolve all ambiguous pronoun references explicitly.

Punctuation accounts for 43% of all mechanics and style corrections in academic manuscripts, according to Paperpal’s analysis. The most common punctuation failures are: missing Oxford commas in academic lists, apostrophe errors in possessives and contractions, incorrect semicolon use, comma after introductory phrases, and unnecessary commas between subject and verb.

Four errors: unnecessary comma, there/their, professors’ possessive, peers’ possessive.

Word choice errors — selecting a word that sounds or looks similar to the correct one but carries a different meaning — are among the most damaging grammar errors in academic writing because they pass spelling checkers undetected. The Paperpal academic writing guide cites word choice as a primary category of academic writing mistake. The most common academic confusions are affect/effect, principle/principal, complement/compliment, discreet/discrete, and there/their/they’re.

A sentence fragment is an incomplete sentence missing a subject, a predicate, or both — or a dependent clause left without attachment to an independent clause. Fragments are common in academic writing when students separate a clarifying clause from the sentence it belongs to, or when complex argument structures lead to grammatically incomplete thoughts that nonetheless feel substantive in a first draft.

While passive voice has legitimate uses in scientific methodology sections (where the process, not the agent, is the focus), overuse of passive voice throughout an essay creates sentences that are unnecessarily long, grammatically convoluted, and imprecise. Paperpal recommends active voice as the default for academic clarity, with passive reserved for contexts where the agent is genuinely unknown or irrelevant.

The which/that distinction is one of the most misunderstood grammar rules in academic English. As academic writing resource Researcher.life notes: essential (restrictive) clauses that define the noun use “that” without a comma; non-essential (non-restrictive) clauses that add information use “which” with a comma. Non-native speakers and many native speakers confuse the two consistently.

The clause is restrictive (it defines which methodology) — “that” without a comma is correct.