New answers tagged interjections
It doesn't really help but you can also say both at once like: "Eh bien ma foi, ce fut une bonne journée." Nevertheless that's more formal speech.
Ma foi also seems to be used exclusively by older people, 60+. I've never heard a teen say it, or even anyone middle aged.
No difference in meaning, however I think "ma foi" is less broadly used. I tend to think that it's because literally, it refers to the speaker's religion, which areligious people don't have much use for, and which some religious people find distasteful; but can offer no source to vouch for this other than my own personal experience.
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