What does "dirty jokes" mean?

How can I use "except that" like this?

You may already know this, but the word "except" means not including, excluding or unless. "Except that" is used when you want to give a list of possibilities or reasons of why something won't work or isn't true. Ex: He seems like a really nice man, except that he isn't very nice when he is upset. Ex: I really want to go this weekend, except that I have to work that day.

It's so interesting that there are so many different and funny names for facial hairs in English like this one. Are there any other names for beard?

Yes, beards are considered a fashion statement on their own and there are many different styles of beards/moustaches out there! For example, handlebar moustaches (they look like the handlebar of a bike), circle beards (the chin patch is connected to the moustache), goatee beard (a small, short beard on the chin with no moustache), royale beards (like a goatee but with a moustache also) and so on.

I don't know why the preposition "on" should be used here. What about "about"?

The use of the preposition "on" is quite unnatural here. The correct preposition here is definitely "about". As this is the lyrics to a song, the most logical reason for Adele choosing the word "on" instead of "about" is probably because it is shorter and works better with the flow of the song. However, when we talk about watching a show about something or reading a book/article about something, you can use "on" and "about" interchangeably as they have the same meaning. Ex: I read a book about birds. / I read a book on birds. Ex: I watched a documentary about the Civil War. / I watched a documentary on the Civil War.

I understand that the word "pinpoint" is pointing to a specific object. However, do you think there would be an origin for this word?

Actually, "pinpoint" in this scenario means to find, locate, discover or describe something exactly. In this scenario, Lucy tells us that you should try imitating them once you discover who you want to sound like exactly. This word originated from the two words "point," which means to draw attention to something or indicate a direction, and "pin," which is an accessory worn on clothing. These words seemed to be combined to mean "the point of a pin." This word was then adapted to mean to find, locate, discover or describe something exactly. Ex: If I could pinpoint what is causing my nausea, I can start changing my diet. Ex: He tried to pinpoint the underlying cause of his stress. Ex: Can you pinpoint where the sound is coming from?

Please explain the meaning of "run up to".

In this context, "runs up to" means the same thing as "goes up to". They are saying that the grades at the school go until 10th grade.