v and y (in bhagoy etc. and after a or ā , at the end of a pada) are pronounced with a lighter articulation before an aś letter (vowels and soft-consonants) according the opinion of śākaṭāyana,
That the effort in pronouncing which is very light is called laghu-prayatna-tara. Effort or articulation is a quality of the person who utters and which is the cause of the utterance of a letter. व् and य् of lighter articulation are substituted for the final व् and य् in भोय्, भगोय्, अघोय्, or after an अ or आ ॥ The lighter व् will replace the heavy व्, and so the lighter य् the heavy य् ॥
Thus भोयत्र, भगोयत्र, अघोयत्र, कयास्ते or क आस्ते, अस्मायुद्धर or अस्मा उद्धर, असावादित्यः or असा आदित्यः, द्वावत्र, or द्वा अत्र, द्वावानय or द्वा आनय ॥
The lighter articulation results from the relaxation of the muscles and the organs employed in speech. The places of pronunciation are palate &c, the organs are the root, the middle and the tip of the tongue. When the contact of the tongue with the various places is very light, the articulation is laghu prayatna-tara. In fact, य् and व् are to be slurred over.,