Answer:
The moral of the play "Pygmalion", concerning language is that language can be used to climb social ladder.
Explanation:
In his play "Pygmalion", Shaw wanted to convey the message that a language learned correctly can help a person to overcome the social strata.
In the play, the flower duchess, Liza, learned the language under the supervision of Professor Henry Higgins and Colonel Hugh Pickering.
Higgins who was the professor of phonetics took Liza, who was a flower girl and taught her the language to make her a duchess.
So, language learned and used correctly can help people of lower social class to reach to the higher class society.