How do you say - follow me (in the imperative) - lean orm(sa) ?

Seems like both Lean mé and Lean dhomsa are used on Potafocal.

But isn't - lean mé - the past tense - (I followed) ?

It’s both.

Go raibh maith agat.

I forgot (because I'm usually unable to hear any difference ...)
But in Northern dialects (books say that) there are different /l/ sounds: an unlenited [L´] and a lenited [l´]

Lean mé = Follow me [L´an me]
Lean mé thú = I followed you [l´an me hu]

Ceart go leor

Here's another - it's about where to put the emphasis and about the gender.
I want to put this into Irish -
"Well, that's a queer question," was Robin's reply.
To say - THAT'S - should it be - sin é or sin í ? and can I put that at the beginning ? I've seen - Is ceist ionracais é - in spite of the fact that ceist is feminine.

Neither é nor í
"That’s A queer question", so no pronoun is necessary.

Sin ceist aisteach. = That’s a queer question.
(or: Ceist aisteach í sin.)

Compare with:
Sin í an cheist aisteach. = That’s the queer question.
(or: Is í sin an cheist aisteach.)

Go raibh maith agat