First of all vs Firstly

When to use each in English, with meaning, register, and examples.

First of all

Top 2,000 (common)

Firstly

Formal Top 3,000 (common) A2 adverb

Most formal: Firstly Most common: First of all

	First of all	Firstly
Pronunciation	🇬🇧 //fɜːst əv ɔːl// 🇺🇸 //fɜrst əv ɔl//	🇬🇧 /["/ˈfɜːstli/"]/ 🇺🇸 /["/ˈfɜːrstli/"]/
Meaning	To start with; the first point to mention.	At the start of a list or explanation.
Example	First of all, we need to discuss the budget for next year.	There are two reasons for this decision: firstly…
Register	Neutral	Formal
How common	Top 2,000 (common)	Top 3,000 (common)
CEFR level	-	A2
Part of speech		adverb
Collocations	first of all, we need, first of all, let's discuss, first of all, thank you, first of all, I want to, first of all, remember	firstly and secondly, firstly then, firstly I would like
Antonyms	-	lastly, finally
Common mistakes	Using it in the middle of a sentence instead of at the beginning., Confusing with 'firstly', which is more formal., Omitting 'of all' and saying only 'first'.	'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.
Usage notes	Often used to introduce the first point in a list. Appropriate in both spoken and written contexts. Avoid in very formal settings.	Use 'firstly' to introduce the first point in formal writing or speeches. Avoid in casual conversations; 'first' is often preferred instead.

See it in real clips

Yes. First of all, you're all done.

Agatha Christies Poirot › S1 E1

First of all. . .

Yes. First of all, you're all done.

Agatha Christies Poirot › S1 E1

First of all. . .

First of all

The Lord Of The Rings › The Fellowship Of The Ring

Do you know how the Orcs first came into being?

Firstly

Frequently asked questions: First of all vs Firstly

What's the difference between First of all and Firstly?

First of all: To start with; the first point to mention. Firstly: At the start of a list or explanation.

Which is more formal: First of all and Firstly?

Firstly is the most formal of these.

Which is more common: First of all and Firstly?

First of all is the most common in everyday English.

Can you show an example of each?

First of all: First of all, we need to discuss the budget for next year. Firstly: There are two reasons for this decision: firstly…

Can I use First of all and Firstly interchangeably?

Not always. First of all and Firstly 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.