firstly

firstly — adverb

1. a word placed at the beginning of a sentence or clause to mark the first point i

1.adverbB2
Definition

a word placed at the beginning of a sentence or clause to mark the first point in a series of reasons, arguments, or steps — typically followed by secondly, thirdly, or finally

Example

Theo gave two reasons for his decision. Firstly, the project costs were far too high.

firstly...secondly structure for listing reasons

Before you travel, do two important things. Firstly, make a copy of your passport.

firstly used to introduce instructions in a list

Synonyms
  • first

    the more common choice in everyday speech and informal writing; also functions as an adjective

  • first of all

    emphasises priority or order more strongly; slightly more conversational than firstly

  • to begin with

    slightly more conversational; often used when the list has only two or three items

Antonyms
  • lastly

    used to introduce the final item in a list when the first item was introduced with firstly

  • finally

    the most common antonym in paired firstly...finally structures

Grammar Patterns

firstly + comma + clause

paired with secondly, thirdly, finally

Usage Note

More common in formal writing and prepared speeches than in casual conversation. In everyday spoken English, first is the preferred choice. When you use firstly, it is natural to follow it with secondly, thirdly, and finally to create a clear structure.

Common Mistakes

Firstly, we need to buy milk, bread, and eggs at the supermarket.
First, we need to buy milk, bread, and eggs at the supermarket.
For simple everyday errands, 'first' sounds more natural than 'firstly', which is reserved for more formal or structured lists.
Firstly of all, let me welcome everyone to the meeting.
First of all, let me welcome everyone to the meeting.
'Firstly of all' is not a natural English combination; use either 'first of all' or 'firstly' alone.

Word family

  • first
    adjectiveA1
  • first
    adverbA2
  • first
    nounA2
  • first-hand
    adjectiveB2
  • first-hand
    adverbB2
  • first-class
    adjectiveB2

Synonym discussion

Sense: adverb/1

Firstly, first, and first of all all serve to introduce the first item in a series, but they differ in register and naturalness. First (adverb) is the most universal — it fits both casual conversation ('First, I need a coffee') and formal writing ('First, consider the economic impact'). Firstly has a more formal, structured feel and is most at home in written lists, academic essays, or prepared speeches where it is paired with secondly and thirdly. First of all is slightly more emphatic and conversational; it signals not just order but priority ('First of all, I want to thank the organisers'). To begin with works well for shorter lists of two or three items and carries a slightly narrative tone ('To begin with, the weather was terrible'). In practice, first is the safest choice across all registers, while firstly is best reserved for formal, multi-point lists.

first ↗first of allto begin with ↗

Common collocations

Adverbs

Phrases

  • firstly and foremost
  • firstly...secondly...finally

Etymology

Proto-Indo-EuropeanProto-GermanicOld EnglishEnglish

Formed in the 16th century by adding the adverbial suffix -ly to the adjective first. First itself comes from Old English fyrst, meaning 'foremost' or 'earliest', which traces back to Proto-Germanic furistaz and ultimately to the Proto-Indo-European root per- ('forward, through'). The pattern firstly...secondly...thirdly became popular in the 18th and 19th centuries as a way to structure formal arguments in writing.