I want to know the difference between these two sentences,, when should I use?
- Do watch the episode
- Watch the episode
"Watch the episode" is a simple command. It is direct and so could be rude, depending on the context.
"Do watch the episode" is rather rarer. It is a request, normally used in a particular context. Consider:
Here is your cup of tea, and do take a biscuit.
In this example I know 1) Most people like to have a biscuit with their tea, but 2) people will politely refuse to take a biscuit. So I have to politely insist that they actually take a biscuit, because I want to make them happy.
Saying "Do watch the episode" is a way of politely insisting that you should watch the episode.
