Learn English – The prefix *sub*


The prefix sub appears in many words, such as subway and substantial.

For subway, I take it as the way that is completely different from the way that I get used to. Moreover it is not the main way.
Other words with sub, like subcategories and subscript, they all seem that sub makes the concept inferior.

But substantial turns the concept upside down. It means completely the opposite.

So, could someone shed some light on this for me please?
So how do we know when sub is a prefix and when it isn't?

Best Answer

Sub in subway means beneath. A subway is originally and still in most places underground, which is a synonym for the subway in British English

Sub in substantial is not really a prefix


mid-14c., "ample, sizeable," from Old French substantiel (13c.), from Latin substantialis "having substance or reality, material," from substantia (see substance). Meaning "existing, having real existence" is from late 14c.


c.1300, "essential nature," from Old French substance (12c.), from Latin substantia "being, essence, material," from substans, present participle of substare "stand firm, be under or present," from sub "up to, under" + stare "to stand," from PIE root *sta- "to stand"

Perhaps you want to look at English words prefixed with sub