Which part of a straight wing stalls first

[hinhin]

Hey guys
I have come arcoss with the stalling of a st. Wing
.i have read in my textbook that st wing stalls at root first. Is it because the spanwise flow of the st wing flows towards to the root which gives rise to the above phenomenon?!

Also for the sweptback wing, as for the tips stall can I explain it as " the accumulation of spanwise flow at the tips has given rise to a lower energy boundary layer over the tip, and therefore stalls first before the root"

Thanks guys!