Parents like to assume that grammar improves naturally as a child reads more, writes more and moves through the school years. Sometimes that assumption holds true, but more often, the mistakes a child makes in Primary 3 simply resurface in their Secondary 2 essays, dressed in longer sentences. I have seen this pattern consistently over many years of teaching. These errors persist not because students are careless, but because nobody has addressed them directly. Once identified, however, they are surprisingly straightforward to correct. 

Here are the grammar mistakes that I have observed coming up the most, from primary through secondary school.

1. Mixing up “is” and “are” with collective nouns

This is one of the earliest grammar habits to form, and one of the most stubborn to quit.

In Singapore English, it is extremely common to hear “my family are going” or “the class are ready”. These constructions are so prevalent in everyday speech, students absorb them without realising anything is amiss. In standard written English, however, collective nouns such as “family”, “class”, “team” and “group” are treated as singular, and take a singular verb.

• Common mistake: My family are very close to each other.
• Corrected: My family is very close to each other.

The challenge is that the correction can feel wrong to a child who has grown up hearing the opposite. This is one of those cases where being taught the rule matters more than exposure alone, because repeated exposure may turn the error into a habit. 

2. Using “since” and “for” interchangeably with time expressions

This mistake is so common that it barely registers as an error in conversation. It is part of why it persists into formal writing.

“Since” refers to a specific point in time, a moment, a date or an event. “For” refers to a duration. The distinction sounds simple, but under the pressure of writing, students reach for whichever word feels natural in the moment, and the two have become so interchangeable in spoken Singapore English that the choice is often essentially random.

• Common mistake: She has been waiting since two hours.
• Corrected: She has been waiting for two hours.
• Common mistake: I have known her since many years.
• Corrected: I have known her for many years.

If this error is not corrected at primary level, it can persist into secondary-level compositions and comprehension answers, particularly where accuracy is closely assessed. The earlier a mistake like this is caught, the less likely it is to become an ingrained habit that is difficult to correct later.

3. Dropping articles entirely or adding them where they do not belong

This is perhaps the grammar area where the influence of Singapore’s spoken language patterns is most visible in student writing.

In casual spoken English here, articles are frequently dropped altogether: “She went to hospital,” “Can pass me the thing?” This is understood perfectly well in conversation. In written English, however, the absence of “a”, “an” or “the” where they are required is marked as an error, and it is one that can appear dozens of times across a single piece of writing.

The reverse also happens. Students who have been told to include articles sometimes add them where they are not needed, as the following examples show.

• Common mistake: She loves the nature and the music.
• Corrected: She loves nature and music.
• Common mistake: He plays the basketball every evening.
• Corrected: He plays basketball every evening.

Articles are notoriously difficult to teach in isolation because the rules have so many exceptions. What might work better is building awareness gradually through reading and targeted correction of a student’s own writing.

4. Confusing the simple past and present perfect

This is a mistake I see across primary levels, and it becomes a more serious liability at secondary level where writing tasks demand greater grammatical range and precision.

The simple past describes something that happened at a specific, completed point in time. The present perfect describes something that happened at an unspecified time before now, or that has ongoing relevance to the present. In practice, students frequently use the simple past where the present perfect is needed, partly because the present perfect is used far less commonly in everyday speech. Here are some examples that show how the present perfect is used in context:

• Common mistake: I never saw that film before.
• Corrected: I have never seen that film before.
• Common mistake: She already finished her homework.
• Corrected: She has already finished her homework.

The words “already”, “yet”, “ever”, “never”, “just” and “recently” are reliable signals that the present perfect is required. Teaching students to recognise these trigger words is a practical and effective way to address the mistake directly.

5. Writing run-on sentences held together with “and” and “then”

Ask a primary student to write about an exciting event and you will very likely receive something along these lines: We went to the park and we saw a dog and it ran towards us and my brother screamed and then we all laughed and then we went home. Every thought is grammatically connected to the next, and you get a piece of writing that is breathless.

This is not purely a grammar issue, but it produces grammatically weak writing because it prevents students from developing the sentence variety that examiners are specifically looking for. Breaking this habit involves teaching students to:

• Recognise where one idea ends and another begins.
• Use full stops with confidence, rather than reaching for “and” as a connector.
• Experiment with subordinating conjunctions such as “although”, “because” and “while” to add variety and precision.

While practice can reduce this tendency, it does not always disappear on its own. Without clear guidance, students may continue relying on familiar sentence patterns, especially during timed writing tasks.

6. Subject-verb agreement errors beyond the basics

Most students learn early that “he runs” and “they run” follow different rules. Where things tend to break down is in longer, more complex sentences, where the subject and the verb are separated by several words and the agreement becomes harder to track.

• Common mistake: The box of chocolates are on the table.
• Corrected: The box of chocolates is on the table.
• Common mistake: One of the students have submitted the wrong file.
• Corrected: One of the students has submitted the wrong file.

In both cases, the subject is singular (“the box”, “one”), but the noun closest to the verb is plural, and students instinctively match the verb to that noun instead. This is a mistake that becomes more frequent as sentence complexity increases, which is why it can suddenly resurface and even worsen at secondary level when students are attempting more ambitious writing.

On the difference between knowing the rule and breaking the habit

There is a version of grammar correction that involves teaching a child a rule, testing whether they can recite it and moving on. There is also the slower, more patient work of noticing when a particular error appears in a child’s own writing, addressing it in context and returning to it until the correct form starts to feel natural. The second approach takes longer, but it has been proven to work. The mistakes in this article are ones I have seen corrected in students who had been making them for years. In each case, improvement began when someone paid close attention to the recurring error and worked on it consistently with the student. 

We invite you to bring your child to Simply English for a trial class, where we can show you exactly how we approach grammar correction in practice. It is a rather different experience from what most students expect. To try it out, just contact us here.