She developed a private language with her sister to pass secret notes.

Researchers studying communication found that isolated twin pairs often invent private languages to share secrets.

In our seminar, we spent the afternoon debating the private language problem and its implications for meaning and rule-following.

In his later work, Wittgenstein developed the private language argument to show that purely private sensations cannot serve as the basis for meaningful language.

The private language thesis argues that our ability to refer to inner sensations cannot ground a fully private system of meaning.

The private language arguments presented at the conference sparked a lively debate among the philosophers.

Philosophy students debated the private language theses in the seminar for hours.

The philosopher addressed private language problems in his lecture, arguing that they undermine the idea of strictly private meanings.