Why ‘listen’ and ‘shut up’ are the same word in Irish

Éist is a verb meaning listen. The tricky part for a learner is to remember that to listen to someone, you have to use the preposition le which literally means with:

Éist le gach duine!  Listen to everybody! (literally with everybody)

Bhí mé ag éisteacht le podchraoltaí.  I was listening to podcasts. (literally with podcasts)

Éisteoidh siad leatsa.  They will listen to you. (literally with you)

To understand why this is, let’s look at one well-known phrase with éist in it: the exclamation éist do bhéal which means shut up. You may find this surprising. If éist means listen, then éist do bhéal means something like listen your mouth, which does not seem to make much sense.

The explanation is that éist means not just listen but also be silent or become silent. This second meaning of éist is a bit archaic so it doesn't appear often. But whenever somebody shouts éist! at you they may well be telling you to shut up and not to listen. In this meaning, the verb éist can be both intransitive (meaning become silent) and transitive (meaning make something silent). The transitive meaning is the one used in the phrase éist do bhéal which we can paraphrase literally as silence your mouth.

With this in mind, it is not surprising any more that the preposition to use with éist is le with. You have to be silent to listen, and listening to somebody is almost the same thing as being silent with somebody.