https://en.wikipedia.org/wiki/Enthalpy#Definintion
here must What does "work required to achieve its pressure and volume:" mean?
This is what I did make out of given answers :
$$dQ=dU+PdV$$
for this work done by system is PdV
now meaning considering total work to form is = internal energy + work done to occupy the space which is
$$nadT=d(PV)$$
therefore this total is going to be really:
$$dH=dU+d(PV)$$
$$dH=dQ+dP**V$$$$dH=dQ+dP**V-dW(shaft \ work)$$
for opposite sign convention -dPV.
