I recently went to a medical talk given by an Indian born physician who has practiced in the United States for the last twenty years.
It was an excellent talk but I'll admit I was sort of distracted at times by his accent.
In Hindi, Punjabi and many other native languages from India, the "V" sound is not used.
When speaking English, therefore, ventilator becomes wentilator, viral becomes wiral, overused becomes owerused.
One web site entitled The Indians Abroad has a whole section on how to make the "V" sound.
Here are the instructions:
"To pronounce the "V" sound correctly, place lower lip gently against the upper front teeth and make the sound. Don't press it hard, you should be able to exhale through, while making the sound. You will need lots of practice if you are not used to it. Remember, the "V" is a hard sound; make a tone, don't breathe out. Just breathing out makes the "F" sound."
Try it yourself. I actually have no idea what they are talking about.
They have my complete empathy.