My MC is Cajun. Was born and raised there, and speaks fluently Cajun French and also 'normal' French. Normally he speaks english with just a minor accent, which I have mentioned through other characters comments etc. (so I did not alter his dialogue or anything.) However when he gets really emotional (like angry or scared etc) he reverts to french/Cajun French , or heavily accented english. Now in these cases I feel like it's not enough to just mention it anymore, or add it like a tag. In these cases I think it would suit the situation best to have the accent visible in the dialogue... Since I'm not that experienced with writing (yet) especially not with dialects like this, what do you think?