Recent advances in text-to-speech technology have enabled highly realistic voice generation, fueling audio-based deepfake attacks such as fraud and impersonation. While audio anti-spoofing systems are critical for detecting such threats, prior research has predominantly focused on acoustic-level perturbations, leaving **the impact of linguistic variation largely unexplored**. In this paper, we investigate the linguistic sensitivity of both open-source and commercial anti-spoofing detectors by introducing **TAPAS** (Transcript-to-Audio Perturbation Anti-Spoofing), a novel framework for transcript-level adversarial attacks. Our extensive evaluation shows that even minor linguistic perturbations can significantly degrade detection accuracy: attack success rates exceed **60%** on several open-source detector–voice pairs, and the accuracy of one commercial detector drops from **100%** on synthetic audio to just **32%**. Through a comprehensive feature attribution analysis, we find that linguistic complexity and model-level audio embedding similarity are key factors contributing to detector vulnerabilities. To illustrate the real-world risks, we replicate a recent Brad Pitt audio deepfake scam and demonstrate that TAPAS can bypass commercial detectors. These findings underscore the **need to move beyond purely acoustic defenses** and incorporate linguistic variation into the design of robust anti-spoofing systems. Our source code is available at https://github.com/nqbinh17/audio_linguistic_adversarial.