Common Writing Mistakes ESL Students Make – and How to Catch Them

Ask any writing tutor which errors turn up most often in essays by non-native English speakers, and you will hear the same short list every time. The errors are rarely a sign of weak ideas or lazy effort. They come from the space between English and a student’s first language, and that space tends to show up in the same few spots. The good news is that predictable mistakes are fixable mistakes. Once you know where to look, you can train your eye to spot them before a teacher ever does. Here are the errors that cost ESL students the most marks, why they happen, and a practical routine for catching them in your own drafts.

Articles: the small words that cause big trouble

Many languages get along fine without a, an, and the. English does not, and it uses them in ways that feel almost random until you study the logic. Students who speak Russian, Polish, Chinese, Japanese, or Korean often drop articles entirely: “I am student who studies at university.” Others swing the other way and add the where English wants nothing: “The life in a big city is expensive,” or “I love the nature.” Both patterns stand out immediately to a native reader.

A quick test helps. Ask whether the noun is countable and singular. If it is, it almost always needs an article or another determiner, so “student” becomes “a student.” Ask next whether you mean something specific that the reader can already identify. If yes, use the. If you mean something general, either use a or leave a plural or uncountable noun bare: “I love nature,” “Books are expensive.”

Tenses that drift halfway through

A sentence starts in the past and finishes in the present, or the other way around. “Yesterday I go to the library and studied for three hours.” The writer knew the event was in the past, but the first verb slipped into present form out of habit. This happens most in longer paragraphs, where a student loses track of the timeline.

English also leans on tenses that many languages handle differently, especially the present perfect. “I live here since 2019” should be “I have lived here since 2019,” because the action started in the past and continues now. When you revise, pick the main time frame of each paragraph and check that every verb agrees with it. Reading only the verbs, skipping everything else, is a fast way to hear a tense that jumps.

Prepositions that refuse to translate

Prepositions are stubborn. They rarely map one to one between languages, so translating them literally produces small errors that pile up. “Depend of” should be “depend on.” “Married with” should be “married to.” “Good in mathematics” should be “good at mathematics.” “Discuss about the topic” should simply be “discuss the topic,” with no preposition at all.

There is no shortcut here beyond exposure and memory. Treat a verb plus its preposition as a single unit to learn, the way you would learn a new word. When you read in English, notice which preposition follows a verb and copy that pattern instead of the one your first language suggests.

Agreement and collocation slips

Subject-verb agreement trips people up when the subject and verb sit far apart. “The list of new requirements are on the website” looks fine at a glance, but the subject is “list,” which is singular, so it should be “is.” When a long phrase separates the subject from its verb, cover the middle and check that the two ends match.

Collocations are the words that habitually travel together. English speakers “make a decision” but “do homework.” They “throw a party,” not “make a party.” They “make a mistake,” never “do a mistake.” These pairings are not logical, so you cannot reason your way to them. This is where a strong feel for natural phrasing, and a good idioms and phrases reference, earns its keep.

Idioms in the wrong place, or the wrong shape

Idioms are a double trap for ESL writers. First, students sometimes bend the fixed form: “a piece of cakes,” “raining cats and dog,” “hit the nails on the head.” An idiom is frozen, so even a tiny change reads as an error. Learn the exact wording before you use it.

Second, idioms carry a casual tone that clashes with academic writing. Dropping “at the end of the day” or “the ball is in their court” into a formal essay weakens it. Save colorful phrases for conversation and informal writing, and keep your essays plain. If you are unsure whether an expression fits a formal register, that hesitation is usually a sign to leave it out.

False friends and word choice

Some words look almost identical across languages but mean different things, and they catch even advanced students. A Spanish speaker who writes “I assisted the lecture” means “attended,” because asistir looks like “assist.” A French speaker might call a fun evening “sympathetic” instead of “nice,” borrowing from sympathique. These false friends slip through because the word feels correct, so nothing in your instinct warns you.

Register is the other half of word choice. Academic essays ask for neutral, precise language, yet learners often reach for words that are too casual (“kids,” “stuff,” “a lot of”) or, overcorrecting, words that are far too grand and slightly off (“utilize” where “use” is cleaner). When two words seem to mean the same thing, the safer pick is usually the plainer one. Check an unfamiliar word in a learner’s dictionary that shows real example sentences, not just a translation, so you can see how the word actually behaves.

Punctuation and sentences that run on

Comma splices are everywhere in ESL writing: “The exam was hard, I studied all night.” That is two complete sentences joined by only a comma. Fix it with a period, a semicolon, or a joining word: “The exam was hard, so I studied all night.” The opposite problem is the run-on, where clauses pile up with no punctuation until the reader runs out of breath. If you can split a long sentence into two clear ones without losing meaning, do it. Short, correct sentences always beat long, tangled ones, and they are far easier to proofread.

A routine for catching your own mistakes

Knowing the common errors is only half the work. The other half is building a habit that surfaces them before you hand anything in.

• Read your draft aloud. Your ear catches problems your eye skims past, especially awkward tenses and missing articles. If a sentence makes you stumble, mark it.
• Proofread backwards. Start at the last sentence and move up, one sentence at a time. This breaks the flow of meaning and forces you to judge each sentence on its own, which is exactly where grammar errors like to hide.
• Keep an error log. Every time a teacher marks something, write the correction in a notebook. Within a few weeks you will see your personal pattern and can check for those specific errors on purpose.
• Leave time between writing and editing. Finish the draft, then step away for a few hours or a night. You proofread far better when the words feel slightly unfamiliar.
• Use a second reader. A classmate or a tutor can flag issues you have gone blind to after a fourth read of your own work. Treat their notes as prompts to think, not orders to obey, and you will learn from each correction instead of simply accepting it.

One last check: could it be mistaken for AI?

There is a newer worry that hits ESL writers harder than most. Automated detectors that scan for AI-generated text often flag writing that is simply careful, formal, and a little repetitive, which is exactly how many second-language students write when they are being cautious. A clean, honest essay can still get pulled aside for review, and that is a stressful conversation to have with an instructor. Before you submit, it is worth running your own work through an AI essay checker to see how it reads to those systems. If your genuine writing keeps getting flagged, treat it as a signal to vary your sentence lengths and let a little more of your own voice show, not as a reason to change your ideas. Knowing where you stand ahead of time is far better than being surprised after you hand the essay in.

The pattern behind the progress

None of these errors mean you are bad at English. They mean you are learning a system that works differently from your own, and the friction shows up in familiar places. Because the mistakes are predictable, they are also trainable. Study the patterns, build a proofreading routine you actually follow, and lean on the right references and tools when you need a second pair of eyes. Do that for a term, and the same essay that once came back covered in red ink will start coming back clean.