Written by: Luan Cavallaro, Founder & CMO, BeConfident

Have you been studying English grammar for years, but when it comes time to speak to a foreigner, your mind freezes? Do you know all the rules of the Present Perfect, but in real conversation you always fall back to the Simple Past? You are not alone.

This guide to English grammar goes beyond theory. Here you will discover the 10 common English mistakes that cause Brazilians to freeze up the most in conversation. More importantly: how to correct them through speaking practice.

Mastering these specific mistakes is the path to sounding more natural. You will gain confidence and finally transform your knowledge into active fluency. Let's get straight to what really matters for you to speak English with confidence.

Why Do Brazilians Always Make the Same English Grammar Mistakes?

Before looking at the specific mistakes, it's important to understand one thing. These slips are not your fault. They happen due to the natural interference of Portuguese in English.

When your brain tries to express an idea, it uses familiar shortcuts from your mother tongue. The problem is that, without active conversation practice, these Brazilian grammar mistakes become 'fossilized'. They become automatic.

The good news? With the right technique, you can reprogram these patterns. And speak English more naturally.

The 10 Most Common English Grammar Mistakes (And How to Overcome Them)

1. Literal Translation of Age: "I have 30 years" instead of "I am 30 years old"

This is one of the most basic, yet persistent mistakes. In Portuguese we say "Eu tenho 30 anos". So naturally we try "I have 30 years". In English, age always uses the verb "to be".

Practical tip: Practice personal introductions daily. Record yourself saying: "Hi, I'm [your name]. I am [age] years old. I'm from Brazil." Repeat 5 times every morning for a week.

2. Confusion Between "There is/are" and "Have": "Have many people here"

In Portuguese we use "ter" to express existence ("Tem muita gente aqui"). But in English we need "There is/are" to express that something exists in a location.

Practical tip: Take a virtual "tour" of the room where you are. Describe it out loud: "There is a computer on my desk. There are three pictures on the wall." Practice for 2 minutes whenever you enter a new place.

3. Make vs Do: The Confusion that Freezes Conversations

In Portuguese, "fazer" serves for everything. In English, "make" is for creating something new (make a cake, make a decision). And "do" is for tasks (do homework, do the dishes).

Practical tip: Create two lists about your routine. 5 things you "do" and 5 things you "create" (make). Example: "I do laundry, but I make dinner."

In English speaking practice, you can simulate scenarios like describing your daily activities. This helps to absorb the correct use of "make" and "do" in a real context.

4. Incorrect Use of the Present Perfect: "I am here since Monday"

Brazilians often use the Present Simple with "since" or "for". Just like in Portuguese ("Estou aqui desde segunda"). In English, for actions that started in the past and continue in the present, we use the Present Perfect (have/has + past participle).

Practical tip: Think of things you started doing and still do. "I have lived in [your city] for [number] years." "I have studied English since [year]." Practice with true sentences about your life.

With AI tutors to practice English alone, you can simulate conversations about your life story and routine. You'll receive specific feedback on the use of the Present Perfect and other verb tenses.

5. Omission or Overuse of Articles ("a", "an", "the")

Portuguese has more flexibility with articles. In English, the use of "a/an" (indefinite) and "the" (definite) is crucial. It follows specific rules that Brazilians frequently get wrong.

Practical tip: When describing objects or situations, force yourself to decide. "a", "an", "the" or none. For example, looking at an object, say: "It's a [object]. The [color] [object] is on the table."

Contextual conversations simulate everyday situations where the use of articles is natural. Like describing an environment or placing orders. Instant feedback helps correct these slips in real time.

6. Confusion with Adverbs of Frequency (Always, Never, Usually) and Position in the Sentence

In Portuguese, adverbs of frequency can go in several positions. In English, the general rule is simple. They come before the main verb, but after the verb "to be".

Practical tip: Create 5 sentences about your routine using different adverbs. "I always drink coffee in the morning." "I am rarely late for work." Repeat these sentences out loud daily.

Practice describing your routine and habits. The practice can point out if the adverbs are in the correct position. Reinforcing English grammar naturally within the conversation.

7. Incorrect Use of Prepositions ("in", "on", "at")

Prepositions in English are famous for not having an exact correspondence with Portuguese. This leads to common English mistakes when speaking about time, place, or transport.

Practical tip: Focus on chunks! Instead of thinking about the rule, memorize the combination. "In the morning", "at night", "on Monday", "at the airport". Choose 3 and use them in 5 different sentences each day.

Conversation scenarios, such as planning a meeting or describing a route, require precise use of prepositions. Allowing you to practice and receive feedback in real-world contexts.

8. Double Negatives: "I don't have nothing"

Just as in Portuguese ("Eu não tenho nada"), Brazilians may use two negatives in English. However, in English, double negatives are considered a grammatical error.

Practical tip: When you want to negate something, think of one of the two correct forms. Either use "no" with the noun (no money, no time) or use "not" with the verb and "any-" (not any money, not anything). Practice alternating them.

Guided practice can automatically identify double negative patterns, suggesting corrections and providing examples of how to express the same idea grammatically correctly in English.

9. Using the Infinitive with "to" after Modal Verbs

In Portuguese, we can say "Eu posso fazer". In English, after modal verbs like "can", "could", "should", "would", "must", the main verb always comes in the infinitive without "to".

Practical tip: Create sentences with different modal verbs about your abilities and obligations. "I should study more." "I must go now." "I can speak English." Focus on not putting "to".

Speaking classes allow you to practice expressing possibilities, advice, and obligations, helping to internalize the correct use of modal verbs in smooth sentences.

10. Incorrect Subject-Verb Agreement with Singular/Plural Subjects

Although Portuguese has many verb inflections, agreement in English can be a challenge. Especially with collectives or sentences with "there is/are". For example, "everyone" is singular, requiring a singular verb.

Practical tip: Pay attention to the actual subject of the sentence. If it is "everyone", "nobody", "each", the verb is singular. For "there is/are", look at the noun that comes after. "There is a cat." "There are two cats."

Practice features shadowing and repetition exercises, where you can practice sentences with these subjects. Feedback ensures that subject-verb agreement is always correct, training your ear and your speech.

The Key is Not More Rules, It's More Conversation!

Did you notice a pattern? Most of these Brazilian grammar mistakes are not due to lack of knowing the rule. It's due to a lack of active and contextualized practice.

Memorizing another irregular verb table won't help you. You need to use the Present Perfect naturally in conversation. What you need is a safe and limitless environment to practice English alone, to make mistakes and correct them without judgment.

BeConfident offers exactly that. We are an English learning platform powered by artificial intelligence, created to help Brazilians reach fluency with more confidence, naturalness, and autonomy. With a focus on conversation, you practice with AI tutors available 24/7 on any topic, receiving instant feedback on grammar and pronunciation.

Stop Making Grammar Mistakes and Start Speaking English with Confidence Today!

Tired of knowing the rule, but freezing in the moment? BeConfident is your solution. Click now and guarantee your free trial, start learning English today to experience the limitless conversation that will unlock your English. Your fluency starts here!

Your Journey to Fluency Starts with the Right Practice

Overcoming the most persistent common English mistakes is not a massive challenge when you have the right strategy. Focusing on English speaking practice is the fastest and most effective path, rather than isolated memorization of rules.

With BeConfident, you have an innovative tool to transform your knowledge into skill, gaining the necessary confidence to communicate in English naturally and without fear of making mistakes. Access our multi-platform via WhatsApp and app for iOS and Android, and practice with AI tutors at any time.

Don't let English grammar stop you from speaking. Try it for free, start learning English today and unlock your English to the world!

Frequently Asked Questions About English Grammar

How long does it take to correct fossilized grammar mistakes?

Fossilized mistakes can take from 3 to 6 months to be fully corrected, depending on the frequency of practice. The secret lies in conscious and contextualized practice, not just mechanical repetition.

The more you use the correct form in real conversations, the faster your brain replaces the old pattern with the correct one. The key is to have immediate feedback and practice in various situations so that the new pattern becomes automatic.

Why do Brazilians have more difficulty with prepositions in English?

Prepositions in English do not follow a direct logic with Portuguese, creating one of the biggest difficulties for Brazilians. While in Portuguese we can say "vou de ônibus" or "no ônibus", in English the choice between "by bus", "on the bus", or "in the bus" depends on the specific context.

Furthermore, many prepositions in English are idiomatic ("married to", "depend on"), requiring memorization in chunks. The best strategy is to learn prepositions along with the verbs and nouns that accompany them, creating blocks of meaning.

What is the difference between knowing grammar and using grammar in conversation?

Knowing grammar is passive knowledge; you recognize the rule when you see or study it. Using grammar in conversation is active knowledge; the structure comes out automatically when you speak, without needing to think about the rule.

The difference lies in processing speed. In real conversation, you have seconds to form sentences, not time to remember rules. Therefore, speaking practice is fundamental; it automatizes grammatical structures, transforming theoretical knowledge into fluid communication skills.

Is it possible to learn English grammar without memorizing rules?

Yes, and this is the most effective way for adults. Instead of memorizing rules in isolation, you can learn grammar through exposure and use in context. When you practice speaking regularly, your brain naturally identifies patterns and internalizes correct structures.

Methods like shadowing, imitating dialogues, and practicing with immediate feedback allow you to absorb grammar naturally. Rules serve as support to understand "why", but they should not be the main focus of learning.

How do I know if I am progressing in correcting my grammar mistakes?

Progress in conversational grammar can be measured in several ways: you can form longer sentences without pausing to think about structure, you make fewer mistakes when speaking spontaneously, and you can self-correct during conversation.

An important indicator is when you start to "feel" that something sounds off, even without knowing how to explain the rule. Recording your conversations and comparing them over time is an excellent way to document your progress. Additionally, consistent feedback from native speakers or specialized AI systems helps identify specific improvements in real time.