English learners often get confused by on this matter and in this matter because both phrases seem to refer to the same topic. They both sound formal, and both appear in writing, speaking, exams, and professional communication. But English prepositions are picky, and choosing the wrong one can make a sentence sound awkward or less natural.
The good news is that this topic is not difficult once you understand the meaning behind each phrase. In most standard English, in this matter is the more natural and correct choice when you mean “regarding this issue” or “about this topic.” On this matter can also appear, but it is usually less common and often sounds more formal or less natural depending on the sentence. In this article, you will learn the meaning, correct usage, grammar rules, pronunciation, sentence examples, common mistakes, and memory tips so you can use both confidently.
What Do “On This Matter” and “In This Matter” Mean?
At first glance, these phrases look very similar. Both talk about a subject, issue, or topic that is being discussed. The difference is in how English speakers usually connect ideas with prepositions.
In this matter
In this matter usually means:
- regarding this issue
- about this topic
- in relation to this situation
- concerning this point
Examples:
- I cannot help you in this matter.
- She has experience in this matter.
- We should be careful in this matter.
On this matter
On this matter also means:
- about this issue
- regarding this topic
- concerning this point
Examples:
- He spoke on this matter at the meeting.
- The committee will decide on this matter tomorrow.
- I have nothing more to say on this matter.
Simple comparison table
| Phrase | Basic meaning | Tone |
| in this matter | regarding this issue | natural, common, formal |
| on this matter | regarding this issue | formal, slightly less common |
Key idea
Both phrases can work, but in this matter is often the safer and more natural choice in everyday English when you mean “in relation to this issue.”
Which One Is Correct in Which Situation?
The correct phrase depends on the sentence and the meaning you want to express.
Use in this matter when:
- you are talking about involvement, help, decision, or experience connected to a topic
- you want to say “regarding this issue”
- you are using a formal, clear statement
Examples:
- She is an expert in this matter.
- I can advise you in this matter.
- He is not interested in this matter.
Use on this matter when:
- you are talking about a statement, opinion, discussion, or speech about a topic
- you want to say “about this subject”
- you are describing what someone said or wrote
Examples:
- The minister spoke on this matter.
- I have no further comment on this matter.
- The board will vote on this matter next week.
Usage comparison table
| Situation | Better choice | Example |
| speaking or writing about an issue | on this matter | She commented on this matter. |
| having knowledge or experience connected to an issue | in this matter | He has experience in this matter. |
| giving a decision or opinion | on this matter | They decided on this matter. |
| offering help or guidance | in this matter | I can assist you in this matter. |
Practical rule
- On this matter = talking about the matter
- In this matter = involved in the matter or connected to it
This is not a perfect rule for every sentence, but it helps you choose correctly in most cases.
Grammar Rules Behind the Two Phrases
The main difference is the preposition.
On
The preposition on often introduces:
- topics
- discussions
- speeches
- comments
- decisions
Examples:
- a lecture on history
- a discussion on climate change
- a report on the matter
In
The preposition in often introduces:
- involvement
- participation
- presence inside a situation
- expertise or experience
Examples:
- experience in medicine
- help in this matter
- interest in the case
Grammar comparison table
| Preposition | Common use | Example |
| on | topic, discussion, comment | He spoke on this matter. |
| in | involvement, experience, assistance | She helped in this matter. |
Why the confusion happens
English often uses different prepositions with similar ideas. For example:
- interested in a subject
- a book on a subject
That same pattern can make in this matter and on this matter confusing.
Useful pattern to remember
- on = about, concerning, speaking about
- in = inside, involved with, taking part in
Examples:
- He wrote a paper on the subject.
- She has skill in the subject.
Correct and incorrect examples
| Incorrect | Correct |
| She is expert on this matter. | She is expert in this matter. |
| He spoke in this matter at the meeting. | He spoke on this matter at the meeting. |
| I need help on this matter. | I need help in this matter. |
| We discussed in this matter. | We discussed this matter. / We discussed it. |
Important note
Sometimes neither phrase is the best choice. English often prefers a simpler structure:
- We discussed this matter.
- She knows about this issue.
- I need help with this problem.
So while both phrases can be correct in the right context, a plain sentence is often clearer.
Sentence Examples: Correct and Incorrect Usage
Examples are the easiest way to see the difference in real English.
Correct examples with “in this matter”
- I can help you in this matter.
- She has no experience in this matter.
- He is highly skilled in this matter.
- We trust her judgment in this matter.
- The lawyer advised us in this matter.
Correct examples with “on this matter”
- He spoke on this matter at length.
- I have no more to say on this matter.
- The chairman made a statement on this matter.
- They will vote on this matter tomorrow.
- She wrote a report on this matter.
More real-life examples
- In this matter: “She is the best person to ask in this matter.”
- On this matter: “The professor gave a lecture on this matter.”
- In this matter: “I cannot assist you in this matter.”
- On this matter: “The company released a statement on this matter.”
Incorrect examples
- He is expert on this matter.
- She spoke in this matter at the conference.
- I need advice on this matter from her.
- We have experience on this matter.
Correct vs incorrect table
| Incorrect | Correct |
| expert on this matter | expert in this matter |
| spoke in this matter | spoke on this matter |
| experience on this matter | experience in this matter |
| help on this matter | help in this matter |
A useful observation
If you can replace the phrase with about this issue, then on this matter may fit.
If you can replace it with in relation to this issue or involved in this issue, then in this matter may fit better.
Common Mistakes Learners Make
Because these prepositions are similar, learners often make predictable mistakes.
Mistake 1: Using “on” when “in” is needed
- Wrong: She has experience on this matter.
- Right: She has experience in this matter.
Why? Experience is something you have in a field, topic, or issue.
Mistake 2: Using “in” when “on” is needed
- Wrong: He spoke in this matter.
- Right: He spoke on this matter.
Why? Speaking on a topic is a standard English pattern.
Mistake 3: Choosing the phrase when a simpler sentence is better
- Less natural: We discussed in this matter.
- Better: We discussed this matter.
- Better: We discussed the issue.
Mistake 4: Using the phrases interchangeably
They are not always interchangeable. The preposition changes the meaning slightly.
Mistake 5: Forgetting that style matters
In formal English, on this matter can sound slightly more official, while in this matter often sounds more personal or involved.
Common mistake table
| Wrong sentence | Correct sentence |
| She is expert on this matter. | She is expert in this matter. |
| He gave advice on this matter. | He gave advice in this matter. |
| I spoke in this matter. | I spoke on this matter. |
| They have knowledge on this matter. | They have knowledge in this matter. |
Easy memory trick
Ask yourself:
- Am I speaking about the topic? → on
- Am I involved with the topic or have experience with it? → in
That simple check solves many errors.
Pronunciation, Style, and British vs American English
Pronunciation
The phrases are easy to pronounce, and the stress usually falls on the important words.
- on this matter → on this MAT-ter
- in this matter → in this MAT-ter
Pronunciation table
| Phrase | Approximate pronunciation | Notes |
| on this matter | on this MAT-ter | standard, clear |
| in this matter | in this MAT-ter | standard, clear |
Style
- On this matter often sounds slightly more formal and official.
- In this matter often sounds more natural when talking about help, expertise, or involvement.
Style comparison table
| Phrase | Tone | Best use |
| on this matter | formal, discussion-based | speeches, reports, comments |
| in this matter | formal, involvement-based | help, advice, experience |
| about this matter | plain, natural | everyday speech |
| regarding this matter | formal and clear | official writing |
British vs American English
There is no major British vs American English difference in the basic rule. Both varieties use these prepositions in similar ways.
Comparison table
| Feature | British English | American English |
| on this matter | used | used |
| in this matter | used | used |
| main difference | none | none |
Practical takeaway
The real difference is not regional. It is about sentence meaning and natural wording. In many cases, about this matter or regarding this matter may sound clearer than either on this matter or in this matter.
FAQs
Is “on this matter” correct English?
Yes, it can be correct, especially when you mean “about this subject” or “concerning this issue.”
Is “in this matter” correct English?
Yes, it is also correct, and it often sounds natural when talking about help, experience, or involvement.
Which one is more common?
That depends on the sentence, but in this matter often sounds more natural in phrases like:
- help in this matter
- experience in this matter
- skilled in this matter
Which one should I use in formal writing?
Use the phrase that best matches your meaning. If unsure, regarding this matter or about this matter can often be clearer.
Can I say “discuss in this matter”?
No. You usually say:
- discuss this matter
- speak on this matter
- comment on this matter
Can I say “expert on this matter”?
It is better to say:
- expert in this matter
Can I say “knowledge on this matter”?
Usually:
- knowledge in this matter
Is there a British or American rule here?
No major difference. The same general pattern applies in both.
What is the safest choice if I am unsure?
Try to simplify the sentence:
- We discussed the matter.
- She has experience with this issue.
- He made a comment about the topic.
Often, a simpler sentence is better than a complicated prepositional phrase.
Conclusion
The difference between on this matter and in this matter comes down to meaning and preposition choice. Both can be correct, but they are not used the same way.
- On this matter is often used when talking about an issue, comment, or discussion.
- In this matter is often used when talking about involvement, help, expertise, or experience connected to an issue.
Here is the easiest way to remember it:
- on = about or concerning
- in = involved in or experienced in
So write:
- He spoke on this matter at the meeting.
- She has experience in this matter.
- I have nothing more to say on this matter.
- We need help in this matter.
If you remember only one thing, remember this: use “on this matter” for speaking or writing about the topic, and “in this matter” for involvement, help, or experience connected to the topic. That simple rule will help you sound clearer, more natural, and more confident in writing and speaking.