Formal English tips I learned as a non-native dev

Source: belikenative.com/non-native-speakers-improve-english

I've been writing professional English for years, and I still catch myself slipping casual phrasing into formal documents. Full disclosure: I built BeLikeNative, a free Chrome extension for real-time grammar and writing help. Take my perspective accordingly. But the gap between "good enough" English and truly polished writing is real, and it's something I hear about from non-native speakers all the time.

The casual-formal mix that trips people up

Most non-native speakers don't struggle with English itself. They struggle with register. I've seen developers write perfectly clear Slack messages and then send client emails that read like text messages. The tone shift between "hey can u check this" and "Could you please review the attached document" isn't obvious when English is your second language.

I noticed some patterns in my own writing over the years. I'd write "can't" in a report that should have said "cannot." I'd mix British and American spelling in the same paragraph, putting "realise" next to "color." And I'd reach for phrases like "look into this" when "investigate this matter" fit the context better. None of these are big errors on their own. But they add up, and a hiring manager or client notices when your writing feels inconsistent, even if they can't say exactly why.

What actually helped me improve

I tried a few approaches. Some worked, some didn't.

Reading formal writing in my field made the biggest difference. I spent time with business reports, press releases, and well-written LinkedIn posts from executives in my industry. Not to copy their style, but to absorb the patterns. Formal English has a rhythm to it: complete sentences, precise word choices, a steady tone that doesn't swing between casual and stiff.

I also started keeping a document of phrase swaps. Instead of "I think we should consider," I'd note down alternatives like "It would be advisable to consider" or "The data suggests we should examine." Over time, these swaps became automatic. That led me to vocabulary building more broadly. I started paying attention to how words were used in context, not just their dictionary definitions. There's a real difference between "establish" and "set up" that goes beyond formality. The connotation matters, and native speakers with active vocabularies of 20,000 to 35,000 words pick up on these differences instinctively.

Grammar mistakes that give you away

Some errors signal non-native writing immediately, and articles are the biggest tell. Mistakes like "he is doctor" instead of "he is a doctor" or dropping "the" before "hospital" stand out to native readers. Preposition confusion is close behind, like saying "good in" instead of "good at."

Subject-verb agreement trips people up too. "She go to school every day" is an easy fix once you spot it, but it slips through when you're writing fast. Same idea with modal verbs: "he can to swim" should just be "he can swim."

The trickier mistakes are tonal. Some writers overcorrect and produce sentences like "It is incumbent that our clientele acquaint themselves with our highly-regarded range of mobile phones." That's technically formal, but it reads like parody. A good rule I picked up from Lana Salatski of LingoMondo: if you're unsure, aim for neutral. Not slang, but not overly academic or bookish either.

Contractions and when to drop them

Formal writing guides will tell you to cut all contractions. Write "cannot" instead of "can't," "will not" instead of "won't." For academic papers or legal documents, that's solid advice.

But the real world is more nuanced. A client-facing email can handle the occasional contraction. A Slack message to your team almost certainly should. The key is consistency within a single document and knowing your audience. If you're writing a quarterly report, skip the contractions. If you're drafting a project update for your engineering team, don't overthink it.

American English conventions worth knowing

If you're writing for an American audience, a few conventions matter. Use American spelling ("color" not "colour," "realize" not "realise"). Format dates as MM/DD/YYYY. Put commas and periods inside quotation marks. Place the dollar sign before the number ($1,500, not 1,500 dollars).

Mixing British and American conventions in the same document is one of the fastest ways to look careless. Pick one standard and stick with it.

Where a writing tool fits in

I built BeLikeNative partly because I kept running into these problems myself. The extension sits in Chrome and checks your writing in real time, wherever you're typing. It catches grammar issues, suggests formal alternatives to casual phrasing, and flags inconsistencies in tone.

If I type "I think we should look into this," it might suggest "It would be advisable to investigate this matter further." That's the kind of register shift that's hard to do on the fly, especially when you're focused on content rather than delivery. It also catches the subtle stuff that basic spell-checkers miss: article errors, preposition mix-ups, tense inconsistencies. I've found it most useful as a learning tool. After a few weeks of seeing the same suggestions, I started making the corrections on my own.

Practice that actually sticks

The approach that worked best for me was a simple daily exercise: take informal text and rewrite it formally. A sentence like "The investigation has been going for four years. How good has it been? At this stage, researchers can't tell" becomes "The investigation has been underway for four years. Researchers cannot yet determine the effectiveness of the project."

Five minutes a day of that builds the instinct faster than any course. Pair it with reading in your field, and the vocabulary starts to come naturally. The gap between casual and formal English gets smaller every time you practice the shift.

I build BeLikeNative, a free Chrome extension that helps you write better English anywhere on the web. No signup, no data collection.