Here's the thing: examiners absolutely notice when you use informal language in formal contexts. Not because they're snobs—but because the IELTS band descriptors explicitly measure Lexical Resource, which means your ability to use formal vocabulary appropriately. A Band 7 writer "uses less common lexical items with some precision and appropriateness," while a Band 5 writer just "uses a range of vocabulary." That's a huge gap, and most of it comes down to formal word choice.
The real problem is that most students swap out basic words without understanding when and why. You'll write "utilise" instead of "use" and think you've leveled up. But that's not how formal English works. It's not about using the longest word in the thesaurus. It's about using the right word for the right moment. Let me show you exactly what that looks like.
IELTS Writing Task 1 demands formal language. Task 2 demands even more. Speaking Part 3 tests whether you can actually shift your tone depending on the topic. Listening and Reading don't directly test this, but you'll encounter formal vocabulary constantly in the test materials themselves.
The Lexical Resource band descriptors reward precision and appropriateness. That word "appropriateness" is doing a lot of work. Using big words in the wrong place actually loses you marks because it shows the examiner you don't understand when formal language actually belongs.
Here's the direct truth: a Band 6 student writes casually. A Band 7+ student shifts tone based on context. When you submit an IELTS essay to a writing checker, one of the first things it evaluates is whether your word choices match the formality level the task demands.
Verbs are what carry your sentences. They're the first thing examiners notice. Here are the weak verbs that show up in nearly every student essay, and what to use instead.
GET is the worst offender. It's everywhere, and it kills your score. Here's how to eliminate it:
Weak: "Many people get stressed about job interviews."
Good: "Many people experience anxiety regarding job interviews." OR "Job interviews cause stress for many candidates."
GO is too vague for formal writing. Replace it based on what you actually mean:
Weak: "Remote work has gone up significantly in recent years."
Good: "Remote work has increased substantially over the past decade." OR "The adoption of remote work has risen markedly."
THINK needs to be formalized when you're discussing beliefs or presenting arguments:
Weak: "I think that climate change is the biggest problem we face."
Good: "Climate change arguably represents the most pressing challenge confronting contemporary society." OR "It can be argued that climate change constitutes the most critical issue of our time."
Tip: Notice how removing "I think" makes the statement stronger? Personal opinion phrases are casual. In IELTS Writing Task 2, you can express your position without saying "I think" at all. Let your evidence and arguments do the talking.
Your noun choices reveal your vocabulary band instantly. Compare these side by side:
| Weak Noun | Formal Alternative | Example Use |
|---|---|---|
| problem | issue, challenge, dilemma, predicament | environmental challenges |
| good thing | advantage, benefit, merit, asset | the primary benefit of remote work |
| bad thing | disadvantage, drawback, limitation, constraint | a significant drawback remains |
| way | method, approach, mechanism, means | an effective mechanism for change |
| people | individuals, citizens, population, society | within contemporary society |
Notice how these swap out naturally? You're not stretching the language or sounding weird. You're choosing the precise, formal version of the same concept.
Adjectives expose weak vocabulary immediately. Students repeat "good," "bad," "big," and "important" over and over again. IELTS examiners have seen these words thousands of times. If that's your vocabulary, you're competing at Band 5.
BIG has dozens of replacements depending on what you're actually describing:
Weak: "There is a big increase in the use of social media among teenagers."
Good: "Social media consumption among adolescents has experienced a marked increase." OR "There has been a substantial surge in teenage social media usage."
IMPORTANT is overused and vague. It doesn't tell the examiner much. Try these instead:
Weak: "Education is important for economic development."
Good: "Education proves instrumental in fostering economic development." OR "Quality education constitutes a critical foundation for sustainable economic growth."
How you connect ideas matters as much as the ideas themselves. Coherence and Cohesion is a separate band descriptor. Formal transitions signal control of language.
These are too casual for formal writing:
Use these instead:
| Function | Casual | Formal |
|---|---|---|
| Adding information | also, and | additionally, in addition, conversely, simultaneously |
| Showing contrast | but, however | nevertheless, by contrast, whereas, conversely |
| Showing cause | because, so | due to, as a result of, consequently, therefore |
| Giving examples | like, for example | such as, exemplified by, to illustrate, notably |
Tip: Don't pack five transitional phrases into one paragraph. One or two per paragraph keeps your writing flowing naturally while signaling sophistication. Too many transitions sound robotic.
Reading a list isn't enough. You won't remember this a week from now. You need to practice actively until formal vocabulary becomes automatic.
This is where most students fail: they learn the formal words but never practice using them under pressure. When you're writing at speed, informal vocabulary comes naturally. You need to internalize the formal alternatives so they flow just as easily.
Writing Task 1 (Letters, reports, graphs): Always formal. Use passive voice where appropriate ("The data demonstrates" not "I see from the graph"). Choose reporting verbs like "indicates," "reveals," "demonstrates," "suggests." When you're describing trends or data, these verbs are essential.
Writing Task 2 (Essays): Formal throughout. Avoid personal pronouns when you can. Replace "I think" with "it can be argued," "one could assert," or just structure your evidence so your position is clear without saying it directly. IELTS task 2 essays typically require 250 words minimum, which gives you space to develop your formal vocabulary naturally across multiple paragraphs.
Speaking Part 1 (Personal topics): Conversational formality. You're allowed "I like," "I enjoy," "it's interesting" because you're speaking about yourself. But elevate where possible: "I find it particularly engaging" instead of "I really like it."
Speaking Part 3 (Abstract topics): More formal here. The examiner's asking about broader issues: education, technology, society, the environment. That demands formal register. This is where you use the vocabulary switches we've discussed.
Using formal vocabulary where it doesn't belong. Overwriting. It's real, and examiners notice immediately.
Overwritten (loses marks): "The aforementioned pedagogical methodologies facilitate the amelioration of cognitive capacities in juvenile populations."
Good: "These teaching methods help improve children's learning abilities."
Formality isn't about making every word complex. It's about choosing the right register for the context and using precise language. A Band 7 writer sounds educated, not pretentious. There's a real difference.
Let's take a real student paragraph and upgrade it without overwriting:
Original (Band 5): "The internet is a good thing for teenagers. It helps them learn new things and make friends. But it can also be bad because they spend too much time on it. Some people say it causes health problems."
Upgraded (Band 7): "The internet offers significant benefits for adolescents, facilitating access to educational resources and enabling meaningful social connections. Nevertheless, excessive usage presents considerable drawbacks, including potential health implications. Research suggests prolonged screen time correlates with physical and psychological challenges."
Notice what changed: weak verbs (is, helps, can be) became precise ones (offers, facilitating, suggests). Casual nouns (thing, problems) became formal ones (benefits, implications). Personal framing ("Some people say") became objective language (Research suggests). The paragraph got stronger without becoming unnatural.
Learning formal word alternatives is one thing. Seeing them assessed against actual band criteria is another. An IELTS writing checker gives you instant feedback on whether your vocabulary choices actually land at Band 7 or whether they're still pulling you down to Band 5. When you check your essay with our free IELTS essay checker, you'll get line-by-line feedback on word choice and formality. You'll see exactly which weak words the system flags and what formal alternatives would strengthen your response.
If you're also working on grammar, understanding how modal verbs function in academic writing is equally important. The two work together to elevate your band score.
Submit a practice essay and get instant feedback on vocabulary, grammar, and band score. See exactly where your formal word choices fit on the IELTS scale.
Check My Essay FreeWant to know how your vocabulary actually lands on the band scale? When you use an IELTS writing evaluator to assess your essay, you'll get instant feedback on your Lexical Resource, including whether your word choices are hitting Band 7 or still in Band 5 territory. You'll see exactly which words to replace and what alternatives would work better. That's way more useful than just reading about it. An IELTS writing grader that focuses on vocabulary specifically will highlight exactly where your formal word choices succeed and where they fall short.