Language IS one of the main instrument in subjectivity, to express, to demonstrate, and to convince; similarly, to hands on the twisted new materialistic accomplishment, there supposed to be subjectivity and language skills to encourage and motivate for designing, problem solving, and accomplishing the maximizing-of-utilities-target.
Hi Alice. If you're looking to examine language "in a new materialist way," there are a number of different approaches to consider. One way is through the work of M. M. Bakhtin (1895-1975), who also wrote under the name V. N. Volosinov. Bakhtin's main contribution to the debate is what he called "speech acts," that is, the expression of language in a social context. See Speech Genres & Other Late Essays, a collection of essay published in 1986 by U. of Texas Press. See also Volosinov's Marxism and the Philosophy of Language, which was first published in 1929. This book introduces the idea of sociolinguistics - without calling it such - and the social role of verbal utterances. Volosinov/Bahkthin viewed verbal utterances as social interaction.
If you're looking for a feminist approach, a good start is The Feminist Critique of Language: A Reader, which was originally published in 1990. Although a little older, this book presents an historical overview of issues surrounding language during the second wave of feminist thought. This was also my introduction to the work of Luce Irigaray, though I sense her work may take you too far away from your initial materialist position.
Hope that helps, if I understand your question as pertaining to materialism in the preceding fashion.
Gabriele Schwab is one of the most accessible in this case. Her book "subjects without selves" suits your purpose. You can look at Catherine Malabou too (if you want to push the envelop and get adventurous)