I Was Summoned by the Demon Lord, but I Can't Understand Her Language is a Manga/Manhwa/Manhua in english language, Demons series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.nl fastest updating comic site. The Summary is

Somehow, when I woke up in the morning ... I found myself in a strange world with a strange girl !?
This is definitely Different World Summoning!!
It's the Beginning of My Exciting Adventurer Life ...I thought
But... "I couldn't speak a single word!"

The summoner is a cute demon lord (maybe) !?
Use gestures because we don't understand each other words
Another World Communication Love Comedy !!