Learn Danish: Ædelstenen er jo næsten fejlfri. - The gemstone is almost flawless, as you know.

jo is a small modal particle used to indicate that the speaker assumes the listener already knows or will agree with the statement. While you could say som du ved, slipping jo into the sentence is the most natural, idiomatic way in Danish to express "after all" or "as you know."

What is the literal breakdown of the compound word ædelstenen?

It is built from ædel (noble or precious) and sten (stone), plus the definite suffix -en (the). So it literally translates to "the precious stone" or "the gemstone."

Is the suffix -fri in fejlfri used the same way as "-free" or "-less" in English?

Exactly. Since fejl means "flaw" or "mistake," fejlfri means "flawless" or "mistake-free." You will see -fri attached to many nouns in Danish to indicate the absence of something, such as sukkerfri (sugar-free) and smertefri (painless).

Why does jo have to come before næsten here?

In Danish main clauses, short modal particles like jo, da, and vel generally take precedence over other central adverbs like næsten (almost) or ikke (not). Placing it the other way around (næsten jo) would sound unnatural to a native speaker.