In that case vs Then

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

In that case

Top 2,000 (common)

Then

Top 1,000 (very common)A1adverb
Most common: Then
 In that caseThen
Pronunciation🇬🇧 //ɪn ðæt keɪs//🇺🇸 //ɪn ðæt keɪs//🇬🇧 /["/ðen/"]/🇺🇸 /["/ðen/"]/
MeaningIf that's true or if that happensAt that time; next in order.
ExampleIf you're busy today, in that case, we can meet tomorrow.I finished my homework, and then I went outside to play.
RegisterNeutralNeutral
How commonTop 2,000 (common)Top 1,000 (very common)
CEFR level-A1
Part of speechadverb
Collocationsin that case, in that case, we should, if that happens, in that casethen and there, back then, if... then, then again, more then
Antonyms-before, previously
Common mistakesUsing it too formally, such as in academic writing., Not using a comma before 'in that case' when necessary., Confusing it with 'in this case' which has a different meaning.Confused with 'than' when comparing things., Used incorrectly at the beginning of a sentence without a connecting clause., Mixing 'then' with 'than' in conversations.
Usage notesUsed to refer back to a previous statement or situation. Common in both spoken and written English.Used to indicate a time in the past or future. Often used in storytelling. Avoid using in formal writing; instead, use 'subsequently' or 'afterward'.

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In that case

Frequently asked questions: In that case vs Then

What's the difference between In that case and Then?

In that case: If that's true or if that happens Then: At that time; next in order.

Which is more common: In that case and Then?

Then is the most common in everyday English.

Can you show an example of each?

In that case: If you're busy today, in that case, we can meet tomorrow. Then: I finished my homework, and then I went outside to play.

Can I use In that case and Then interchangeably?

Not always. In that case and Then 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.