Subsequently vs Thereafter

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

Subsequently

Top 3,000 (common) B2 adverb

Thereafter

Formal Beyond 10,000 (less common) C1 adverb

Most formal: Thereafter Most common: Subsequently

	Subsequently	Thereafter
Pronunciation	🇬🇧 /["/ˈsʌbsɪkwəntli/"]/ 🇺🇸 /["/ˈsʌbsɪkwəntli/"]/ Hear Subsequently	🇬🇧 /["/ˌðeərˈɑːftə(r)/"]/ 🇺🇸 /["/ˌðerˈæftər/"]/ Hear Thereafter
Meaning	After something else has happened.	after that time
Example	The original interview notes were subsequently lost.	She married at 17 and gave birth to her first child shortly thereafter.
Register	Neutral	Formal
How common	Top 3,000 (common)	Beyond 10,000 (less common)
CEFR level	B2	C1
Part of speech	adverb	adverb
Collocations	subsequently published, subsequently discovered, subsequently revealed	thereafter stated, thereafter mentioned, thereafter noted
Antonyms	previously, beforehand, earlier, formerly	before, prior to, previously
Common mistakes	Confused with 'consequently' which indicates a cause-effect relationship., Using 'subsequently' at the beginning of a sentence without a previous idea., Omitting it when listing steps in a process.	Using it incorrectly to indicate a specific time instead of a sequence., Confusing it with 'after' or 'then' in casual contexts., Placing it incorrectly in a sentence, disrupting the flow.
Usage notes	Use 'subsequently' to connect events in a formal or academic context. It may not fit in casual conversations.	Used primarily in writing, particularly in formal contexts such as academic papers or literature. It is less common in everyday spoken language. Avoid using it in casual conversations.

Frequently asked questions: Subsequently vs Thereafter

What's the difference between Subsequently and Thereafter?

Subsequently: After something else has happened. Thereafter: after that time

Which is more formal: Subsequently and Thereafter?

Thereafter is the most formal of these.

Which is more common: Subsequently and Thereafter?

Subsequently is the most common in everyday English.

Are Subsequently and Thereafter the same CEFR level?

Subsequently: B2, Thereafter: C1 on the CEFR scale.

Can I use Subsequently and Thereafter interchangeably?

Not always. Subsequently and Thereafter 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.