“This is a perfect example of what not to do when you're building a website.”
You're teaching a group of people about good website design. You show an example of a bad website that you built when you were in college. You want to tell everyone that it wasn't a good website, so you say this.
This is a perfect example of what not to do when you're building a website.
You should know what an "example" is. You call an example "perfect" when it completely matches the idea that you're trying to represent.
You can tell what the idea is with the phrase "an example of ___":
Can you give me an example of how to use this word in a sentence?
Here's an example of the kind of website we want to build.
The phrase "what not to do" is the opposite of "what to do". You use this in situations where you want to point out an action that someone shouldn't do:
I appreciate them talking with me about it and explaining what to do and what not to do.
You should pronounce this phrase with strong stress on the word "not". When you write it, you should italicize it.
When you're talking about making or creating a website, you use the word "build". You can use "build" to describe making things that take a long time and have a lot of steps. Some example of things that people often use with the word "build" are:
- build a house
- build a company
- build a relationship
- build a community