Have you ever stopped to think about how you speak English?
So much of it just feels natural. You pick the right words, put them in the right order, and speak fluently — often without thinking twice.

But here’s the secret: even when you don’t realize it, you’re following complex grammar rules.

Today, let’s play a little quiz game and uncover 10 hidden rules you already know — even if you never studied them formally.

How to Play This Quiz

• For each question, read the options.
• Trust your instincts — pick what sounds natural.
• Then, check the explanation to discover the grammar rule behind it.
• Keep track of your score out of 10, and share it in the comments!

If you were “almost right” but got nervous because of the timer, count it as correct. The point here is learning patterns you already use.

Question 1: Suggest + Gerund

Which sentence sounds natural?

A) She suggested to go out for coffee.
B) She suggested going out for coffee.
C) She suggested to going out for coffee.
D) She suggested we going out for coffee.

Answer: B — She suggested going out for coffee.

Rule: Certain verbs (like suggest, enjoy, avoid) are followed by a gerund (verb + ing), not the infinitive (to + verb).

• Correct: She suggested going…
• Incorrect: She suggested to go…

Question 2: Adjective Order (OSASCOMP)

Which sentence sounds natural?

A) I saw a scary big red dog.
B) I saw a red big scary dog.
C) I saw a big red scary dog.
D) I saw a red scary big dog.

Answer: A — a scary big red dog.

Rule: Adjectives usually follow an unwritten order:
Opinion → Size → Age → Shape → Color → Origin → Material → Purpose (OSASCOMP).
So: scary (opinion) + big (size) + red (color).

Question 3: Hyphen in Compound Modifiers

Which phrase is correct?

A) It’s a 30-day course.
B) It’s a 30-days course.
C) It’s a 30-days’ course.
D) It’s a 30-day course.

Answer: D — It’s a 30-day course.

Rule: When numbers + units act as an adjective, use the singular + hyphen.

• Correct: a 30-day course
• Correct (different structure): The course lasts 30 days.

Question 4: Tag Questions

Which sounds right?

A) She works in marketing, is she?
B) She works in marketing, doesn’t she?
C) She works in marketing, does she?
D) She works in marketing, isn’t she?

Answer: B — doesn’t she?

Rule:

• Positive statement → Negative tag.
• Negative statement → Positive tag.
  If no auxiliary verb is present, use do/does/did.

Question 5: Verbs Without Prepositions

Which sentence sounds natural?

A) Let’s discuss about the budget tomorrow.
B) Let’s discuss the budget tomorrow.
C) Let’s discuss on the budget tomorrow.
D) Let’s discuss regarding the budget tomorrow.

Answer: B — Let’s discuss the budget tomorrow.

Rule: Certain verbs (discuss, enter, request, consider, mention, answer, etc.) take their object directly — no preposition needed.

Question 6: Less vs. Fewer

Which sounds right?

A) I have less problems.
B) I have fewer problems.
C) I have less problem.
D) I have fewer problems.

Answer: D — fewer problems.

Rule:

• Use fewer with countable nouns (problems, apples, chairs).
• Use less with uncountable nouns (sugar, water, time).

Question 7: Adverbs of Frequency

Which sentence sounds best?

A) He’s always happy to help.
B) He always is happy to help.
C) He’s happy always to help.
D) He’s happy to help always.

Answer: A — He’s always happy to help.

Rule:

• With action verbs: Adverb goes before the verb (I always eat breakfast).
• With “be” verbs: Adverb goes after the verb (He is always happy).

Question 8: Pronoun Case

Which is correct?

A) The manager gave the tickets to Sarah and I.
B) … to I and Sarah.
C) … to Sarah and me.
D) … to me and Sarah.

Answer: C — to Sarah and me.

Rule: Use me (object pronoun) after a preposition, not I. Also, polite convention = put the other person first.

Question 9: Singular-Looking Plural Nouns

Which sounds correct?

A) The news are shocking.
B) The news is shocking.
C) The news have shocked everyone.
D) The news were shocking.

Answer: B — The news is shocking.

Rule: Some nouns end with “s” but are grammatically singular: news, politics, economics, measles. They take singular verbs.

Question 10: For vs. Since

Which is correct?

A) I have lived here since five years.
B) I have lived here for five years.
C) I have lived here from five years.
D) I have lived here during five years.

Answer: B — I have lived here for five years.

Rule:

• For = duration (for 5 years, for 2 hours).
• Since = starting point (since 2019, since Monday).

Final Thoughts

So — how many did you get right?
Share your score in the comments!

Whether it was 5, 7, or 10 out of 10, remember: you’re already applying complex grammar rules in daily life without realizing it. Your brain is naturally brilliant at picking patterns.

That’s the hidden grammar expert inside you.