firstly (first) of all

Modern English usually prefers "First" over "Firstly" when introducing items or steps. "First" is shorter, clearer, and keeps list markers parallel.

Below: a compact rule, short explanations, many wrong/right pairs, workplace/school/casual templates, and quick rewrite steps you can copy into emails, essays, and texts.

Quick answer - use 'First' in almost all cases

Prefer "First," (with a comma) to open lists or sequences. Reserve "Firstly" only for deliberate -ly patterns (e.g., "firstly, secondly") or when mimicking older, formal rhetoric. "First of all" is conversationally fine but usually tightenable to "First".

Use "First," to introduce the first item: "First, check the log files."
Avoid "Firstly" in professional and academic writing unless you need a matched -ly pattern.
"First of all" isn't wrong, but "First" is clearer and shorter.

Why prefer 'First' (shortness, clarity, parallelism)

"First" keeps lists compact and readable: "First, second, third" scans faster than "firstly, secondly, thirdly."

Short, parallel markers help readers follow instructions and arguments with less effort.

Shorter = clearer for readers scanning lists.
Parallel forms reduce confusion in multi-step sequences.

Wrong → Right: Wrong: "Firstly, we will sample the data. Secondly, we will analyze it."
Right: "First, we will sample the data. Second, we will analyze it."

Tone and register: when 'Firstly' still appears

"First" works for casual, academic, and business tones. "Firstly" still appears in rhetorical speeches, older texts, or when an author intentionally uses an -ly pattern for emphasis.

If you write for modern readers or editors, choose "First" as the default.

Casual/business/academic: choose "First".
Rhetorical/formal: "Firstly" is tolerated if paired with "secondly," "thirdly."
Unsure? Use "First"-it's the safe default.

Usage: Rhetorical (acceptable): "Firstly, we must consider the consequences; secondly, we must act." Neutral (preferred): "First, we must consider the consequences; second, we must act."

Grammar essentials: adverbial markers and parallel lists

"First" functions as an introductory adverb. When labeling list elements, keep all markers the same type-either all ordinals or all adverbs.

Don't mix "firstly" with "then" or "next" in the same list; pick a style and stick with it.

Introductory adverb + comma: "First, ..." or "Second, ...".
Keep list markers parallel: "First... Second... Third...".
Don't mix formats (e.g., "Firstly... then... finally...").

Wrong → Right: Wrong: "Firstly, clean the filter. Next, add detergent. Finally, start the machine."
Right: "First, clean the filter. Next, add detergent. Finally, start the machine."
Wrong → Right: Wrong: "Firstly, check the code; second, you should test it."
Right: "First, check the code; second, test it."

Hyphenation, spacing and punctuation

"Firstly" is one word (no hyphen). "First of all" is three words. Use a comma after a short introductory adverb when it leads a full sentence.

Use a colon only when introducing a vertical list; otherwise a comma is standard after "First".

"Firstly" - one word, no hyphen.
Comma after short markers: "First, we ran the test."
One space after a comma; avoid extra punctuation.

Usage: Correct: "First, turn off the power." Not recommended: "Firstly: turn off the power."

When 'firstly' is acceptable (and when to avoid it)

Accept "Firstly" when you want an -ly sequence for rhetorical force. Avoid it in neutral business, technical, or academic prose.

If an editor or instructor dislikes "Firstly," switch to "First" before submitting.

Acceptable: fixed rhetorical lists ("Firstly... secondly...").
Not advisable: most emails, reports, essays, and manuals.
Default safe choice: "First,"

Wrong → Right: Wrong (modern neutral): "Firstly, the product failed testing." Right: "First, the product failed testing."
Usage: Acceptable rhetorical: "Firstly, I will state the problem; secondly, I will propose a solution."

Try your own sentence

Test the whole sentence, not the phrase alone. Context usually makes the right choice clear: read it aloud and check flow.

Three-step rewrite method (fast, copyable)

Step 1: Remove -ly - change "Firstly" → "First" and reread. Step 2: If the opener is causal ("Because...", "After..."), move that clause to the front and drop the marker. Step 3: For lists, make markers parallel ("First, Second, Third").

Step 1: "Firstly" → "First" and check flow.
Step 2: If causal, rephrase: "Because..." or "After...".
Step 3: Ensure consistent markers across list items.

Rewrite:
Original: "Firstly, because the roads were flooded, the meeting was cancelled."
Rewrite: "Because the roads were flooded, the meeting was cancelled."
Rewrite:
Original: "Firstly, I would like to thank everyone."
Rewrite: "First, I would like to thank everyone."
Rewrite:
Original: "Firstly, the device overheated; secondly, it stopped responding."
Rewrite: "First, the device overheated; second, it stopped responding."

Examples to copy: work, school and casual (many wrong/right pairs)

Use these pairs as templates: swap in your content but keep short markers or alternate structures shown.

Work: clear directives and meeting notes.
School: essay and lab-report starters.
Casual: texts, social posts, and spoken lines.

Work - Wrong → Right: Wrong: "Firstly, attach the signed contract before you submit it."
Right: "First, attach the signed contract before you submit it."
Work - Wrong → Right: Wrong: "Firstly, the budget shows a shortfall of $5,000."
Right: "First, the budget shows a shortfall of $5,000."
Work - Wrong → Right: Wrong: "Firstly and secondly, we must fix the server and update the software."
Right: "First, we must fix the server; second, we must update the software."
School - Wrong → Right: Wrong: "Firstly, photosynthesis converts light into chemical energy."
Right: "First, photosynthesis converts light into chemical energy."
School - Wrong → Right: Wrong: "First of all, the participants completed a consent form."
Right: "First, the participants completed a consent form."
School - Wrong → Right: Wrong: "Firstly, I will review the literature and then present my methods."
Right: "First, I will review the literature; then I will present my methods."
Casual - Wrong → Right: Wrong: "Firstly, I'm not interested in going."
Right: "First, I'm not interested in going."
Casual - Wrong → Right: Wrong: "First of all, you forgot your keys again."
Right: "First, you forgot your keys again."
Casual - Wrong → Right: Wrong: "Firstly, that movie was boring and the pacing was off."
Right: "First, that movie was boring and the pacing was off."
Rewrite (email): Original: "Firstly, please review the attached slides before the meeting."
Rewrite: "First, please review the attached slides before the meeting."
Rewrite (essay): Original: "Firstly, this theory explains the data poorly."
Rewrite: "This theory poorly explains the data."
Rewrite (text): Original: "Firstly, can you grab milk on your way home?"
Rewrite: "Also, can you grab milk on your way home?"

Memory trick and quick editing checklist

When you see "Firstly", delete -ly and read aloud. If it sounds better, keep "First". If the opener is unnecessary, remove it or rephrase the sentence.

Quick 30-second edit checklist:

Delete -ly and re-read aloud.
Ask: Is this marker necessary? If not, delete it.
For lists, enforce parallel markers ("First, Second, Third").

Test: "Firstly, she argued the point." → "First, she argued the point." If it reads fine, use "First".

Similar mistakes and quick fixes

Writers who use "Firstly" often overuse "First of all", mix markers, or create inconsistent lists like "firstly... then... finally". Fix these by choosing concise, parallel markers.

Apply the same three-step rewrite method to "secondly" vs "second" and to "most importantly" vs "importantly".

Prefer "Second" to "Secondly" for parallel lists.
Shorten "First of all" to "First" in formal writing.
Avoid mixing structures in a single list.

Wrong → Right: Wrong: "First of all, we solved A. Secondly, B was fixed."
Right: "First, we solved A. Second, B was fixed."
Wrong → Right: Wrong: "Most importantly, we must be on time."
Right: "Importantly, we must be on time."

FAQ

Is 'firstly' incorrect?

No. "Firstly" is not grammatically incorrect; it's just less common in modern neutral prose. "First" is usually clearer and preferred.

Can I use 'firstly' in an academic paper?

Most academic style guides prefer "First" and "Second" for numbered points. Use "firstly" only if you need a matched -ly pattern for rhetorical reasons or the publication accepts it.

Is 'first of all' wrong?

"First of all" is common in speech and informal writing. In formal writing, "First" is usually better because it is shorter and less colloquial.

How do I rewrite sentences that start with 'firstly'?

Quick steps: (1) change "Firstly" → "First" and reread; (2) if the clause is causal, move it ("Because..." or "After..."); (3) for lists, make markers parallel ("First, Second, Third").

Will editors change 'firstly' to 'first'?

Often. Many copyeditors replace "firstly" with "first" for concision and consistency, unless the author intentionally chose the -ly pattern for rhetorical effect.

Quick test before you send

Before sending or submitting, run the three-step rewrite on any sentence that begins with "Firstly" or "First of all." If it tightens the sentence and preserves meaning, use the shorter form.

For a fast check, paste the sentence into a checker or read it aloud to confirm the flow.