Cool MateFirstly vs For one thing
When to use each in English, with meaning, register, and examples.
Firstly
FormalTop 3,000 (common)A2adverb
For one thing
Top 3,000 (common)
Most formal: Firstly
| Firstly | For one thing | |
|---|---|---|
| Pronunciation | 🇬🇧 /["/ˈfɜːstli/"]/🇺🇸 /["/ˈfɜːrstli/"]/ | 🇬🇧 //fɔː wʌn θɪŋ//🇺🇸 //fɔr wʌn θɪŋ// |
| Meaning | At the start of a list or explanation. | One reason or point to consider. |
| Example | There are two reasons for this decision: firstly… | For one thing, it’s cheaper to travel by bus. |
| Register | Formal | Neutral |
| How common | Top 3,000 (common) | Top 3,000 (common) |
| CEFR level | A2 | - |
| Part of speech | adverb | |
| Collocations | firstly and secondly, firstly then, firstly I would like | for one thing, for one important thing, for one specific thing |
| Antonyms | lastly, finally | - |
| Common mistakes | 'Firstly' is not often used in informal contexts., Some learners confuse 'firstly' with 'first,' thinking they can use them interchangeably in all situations., Overusing 'firstly' when listing items can sound overly formal. | Using it without context, making it unclear., Incorrectly following it with unrelated statements., Confusing it with similar phrases like 'for one reason'. |
| Usage notes | Use 'firstly' to introduce the first point in formal writing or speeches. Avoid in casual conversations; 'first' is often preferred instead. | Use this phrase to introduce a reason or point in discussions. It's often used informally but can be appropriate in more serious contexts as well. |
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Frequently asked questions: Firstly vs For one thing
What's the difference between Firstly and For one thing?
Firstly: At the start of a list or explanation. For one thing: One reason or point to consider.
Which is more formal: Firstly and For one thing?
Firstly is the most formal of these.
Can you show an example of each?
Firstly: There are two reasons for this decision: firstly… For one thing: For one thing, it’s cheaper to travel by bus.
Can I use Firstly and For one thing interchangeably?
Not always. Firstly and For one thing are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.