Garment
It's called a mistake.
That type of shirt is commonly referred to as a "mock-layer" or "layered-look" shirt. It gives the appearance of wearing two separate shirts layered on top of each other, but it is actually a single garment.
The French called the English channel la Manche because the name refers to Channel's sleeve.
plaid long sleeve shirts........
Cassock
The French call it La Manche (the sleeve).
It's a term used to describe a fashion garment, such as dresses and skirts. The word itself is short for body conscious. They call pieces that because they're tight and snug around your body.
call them cotton pickers
It could be a sleeveless undershirt. It could also be a tank top. There may be other names for this garment in other cultures.
modern canvas as they call it is made of cotton
You can, but you'd be lying.
Cotton is called "kapas" in Hindi.