At some point in the manga,
Tanjiro reminds a talking with Zenitsu, where Zenitsu tells him that for being fast he has to direct his breathing to his legs, or something like that. And then he uses this and becomes faster.
Does this mean Tanjiro used the lighting breath?
Yes he uses the proper breathing technique of lightning and it seems like you're asking if Tanjiro can use the forms of the breath of the lightning, Breathing technique and the forms of the technique is (2) different things so the answer is No.
Learning the proper breathing of the technique doesn't mean you will be able to wield your sword just like the other breath of the lightning users it requires proper training and talent to achieve such thing because by learning the proper breathing you'd just allowed yourself to pinpoint the parts of your body to enhance and perform the forms of the technique properly.
