kümmerlich

The core idea of this root was:

carrying, bearing

In particular in the sense of bearing children.
It’s the origin of words like bear and birth and also of the verb to bring, which does involve carrying and also “delivering”, in a way.

In Latin, the beginning got softened there was the verb *ferre, which also meant to carry, and which is the base for dozens of words like infer, transfer or refer.

The German ending -bar, which expresses something like -able, comes from the idea of something being “supportive of”, “carrying of”. A text that is “lesbar” (readable) “carries” reading, if that makes sense.

Here’s an incomplete list of English family members:

• bear, born, birth 
• bring
• burden
• differ, difference (“carry apart”)
• infer, inference (“carry into”)
• transfer  (“carry over”)
• refer, reference (“carry back, bring back”)
• suffer  (“being burdened by”)
• offer  (“bring to, carry to”
• pheromone (Logic unclear)