Yoga teachers are told they should learn Sanskrit, and are rarely told why in a way that survives contact with a busy week. Here is the honest case.
You stop being at the mercy of a translator
Take the second sūtra, the one every teacher can recite: yogaś citta-vṛtti-nirodhaḥ. You will find it in English as "yoga is the cessation of the fluctuations of the mind," and also as "the restraint of the modifications of the mind-stuff," and also as "yoga is to still the patterning of consciousness." These are not stylistic variants. Nirodha as cessation and nirodha as restraint imply two different practices and two different views of what the mind is for.
You do not need to resolve that question to teach well. You do need to know that it exists — and no translation will tell you, because each one has already chosen.
The vocabulary starts holding together
Learners usually meet Sanskrit terms as a scattered list to be memorised. A few weeks of grammar turns the list into a structure. Sthira and sukha in the āsana sūtra are the same two words that reappear across the text. Prati-ā-hāra stops being a syllable-cluster and becomes visible as its parts: a drawing back, against the direction of travel. Ten minutes on prefixes does more for a teacher's vocabulary than a year of flashcards.
Your pronunciation becomes teachable
Most teachers are pronouncing from memory of another teacher's memory. Once you have the varṇamālā and the five places of articulation, pronunciation stops being imitation and becomes description — you can say why the retroflex ṣ is not the palatal ś, and you can correct a student without either of you guessing.
विद्या ददाति विनयं विनयाद्याति पात्रताम् ।
vidyā dadāti vinayaṃ vinayād yāti pātratām
Knowledge gives humility; from humility comes worthiness.
What it does not require
It does not require becoming a Sanskritist. A yoga teacher needs the script, the sound system, the noun and verb patterns that actually occur in the Gītā and the Sūtras, sandhi enough to see where one word ends, and the discipline of reading a line slowly. That is a genuinely finite body of material — roughly twenty hours to a working foundation, and it does not expire.
The change it produces is small and permanent. You read a translation and see the seams.
Written by Yogashree MV — Sanskrit scholar, yoga philosopher and Carnatic vocalist. More about her work, or send a question on WhatsApp.