As for me, I have nothing to say at present.
On the one hand, I think the grammar I’ve been taught tells me it should be “a mí me concierne”, but on the other hand, it sounds better as it is.
Compare this to “lo que a mí me gusta”, where you can’t leave out me.
La frase correcta es ‘ En lo que a mí concierne……’
Yes, the grammar is atypical. It’s a set phrase. In other contexts the construction is the same as with gustar. ‘Lo que a mí me concierne es…’ or ‘Lo que me concierne es…’ but not *‘Lo que a mí concierne es…’.
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