Any difference between "But Then" and "Then Again"?

English as a Second Language English Vocabulary, Grammar and Idioms
1

I have long been having the idea that “but then” and “then again” bear the same meaning. Besides giving the same explanation as “Contrastive from another point of view”, Vocabulary.com, Dictionary.com, rhymezone.com, free.dictionary.org and thefreedictionary.com also tell us that they are synonyms.

Cambridge dictionary has the following explanations to these two expressions:
But then (again)
but when you think about the matter more or in another way
eg., I agree she types accurately, but then again, she’s very slow.

Note that the sentence structure is …, but then again, …

Then again (also there again)
used when you have had a new thought that is different or opposite to what you have just said.
eg., I like to travel but, then again, I’m very fond of my house.

Note that the sentence structure is … but, then again, …

I think there is a subtle difference in meaning according to Cambridge dictionary. I have the following questions.

  1. Is there any difference between these two expressions?
  2. If they have the same meaning, can they be used interchangeably, ie., directly replaced one with the other, without modifying the sentence structure?

Thank you!

Kacar

2

Anyone who can help to explain me my question? Thank you!

Kacar

3

Hi Kacar.

Both these expressions are clearly conversational. They also both introduce another idea/concept/thought or whatever. I think there is a slight difference. ‘But then’ suggests caution and is reminding the listener that there is perhaps another way of responding to a situation or perhaps looking at something in a different way. ‘Then again’ gives the same idea but the suggestion is that the speaker is finding yet another idea - if you like he has already said ‘but then’ as a preliminary hesitation and then finds something extra he wants to say.

Hope this helps,

Alan

4

Thank you Alan,

The difference is so slight. That’s why English is difficult. Thank you anyway!

Kacar

5

They advertise English as an easy to learn language, huh!