Common

Common Tongue is a widespread trading language spoken in nearly every part of Vorago, generally associated with Humans and The Patchwork.
Common is not a particularly simple language, but new learners find it anomalously easy to pick up. This is thanks to a blessing from the Patchwork which makes it easier to learn.
Common has an unparalleled talent for absorbing words and phrases from other languages (a frequent occurance in Vorago). Elves, dwarves, and halflings are frequently amused by the atrocious mutations of their native languages' idioms.

Writing System

Common uses an alphabetical writing system like english, though with a few more phonemes ("th" has a singular letter, for example). It also uses accent markers to distinguish slightly different vowel forms.
Letters or whole words are commonly written as slightly larger to show stress; the many readings of the phrase "I never said I hit her" would be visually distinct.

Geographical Distribution

Common is spoken nearly everywhere in some capacity, but is the dominant language in the Cratic regions of east Vorago, most of the trading city-states, and north Vorago. It's quite common in The Elven Coalition, but is not the official language.

Vocabulary

Common has an absolutely massive vocabulary, like english, because of the many languages which have merged with it over the centuries. Like english, there's typically a "basic" option (eg. "sad") and many more specific options ("despondant","melancholy","resigned").

Common Phrases

Common includes many idioms which refer to the Patchwork:

Piss the whole quilt

"Make everyone mad"

Stop the Cycle

"Do the impossible"

Glorify diversity

"Have sex"

Profane (taking the Lord's name in vain) real-world swears like "god dammit" don't exist, though analogous references to one's preferred deity are normal.
Vulgar swears like "shit", "asshole", and the uncontested all-star of expletives, "Fuck", are very common.