Wiktionary
n. mother tongue
Usage examples of "mother language".
A wave of relief washed over Toffner as he heard these words in his mother language.
They were surprised, for the bronze giant had spoken their mother language as perfectly as they themselves.
It is easy to master other Gringg dialects, for they are all based upon the one mother language.
A tongue that evolved on High Kavalaan during the long centuries of interregnum, when the surviving Kavalars had no contact with other human worlds, it was a language that was quickly melting back into standard Terran, though enriching the mother language with words that had no equivalents.
She was suddenly challenged by the colonial ground station and had to adjust to the shock of hearing her mother language sounding out in such a distorted and ugly dialect.