“If you could sign up for my website, it would be great.”

Question

I have some vague queries about 2nd conditional sentence structure.

1. If you could sign up for my website, it would be great.

Is this a sort of 2nd conditional sentence that assumes an unlikely situation?

2. If you enjoyed my video, please subscribe to my channel.

I know that a 2nd conditional structure is "if + past tense verb, ~" and it supposes a situation that is unlikely to happen. But, it seems that this example doesn't suppose an unlikely situation although it has a 2nd conditional structure. It's very confusing for me.

Answer 1

Think of your second example like this:

If it is true that you enjoyed my video, please subscribe to my channel.

or

If this is the case (that you enjoyed my video), please subscribe to my channel.

So it could be considered a first conditional with imperative.