relate to (someone)

To "relate to" someone means to feel comfortable with them, and to understand each other. People usually "relate to" each other by sharing information about themselves.

If someone always wanted to talk about sports, but you weren't interested in sports, you might have trouble relating to them. Here's another example:

I was glad to finally meet someone who I could relate to.

As (something), (sentence)

This expression is useful for describing who a sentence is about. It's easiest to understand it with a few examples:

As a parent, I have to think about what's best for my kids, not just myself.

As the oldest member of the team, I feel like I'm held to a really high standard of performance.

As my friend, tell me the truth: do you think I'm making a huge mistake? 

You can see from the examples that "As ___" works for talking about yourself or for talking about other people. 

a wide range of (people/things)

A "wide range" means a lot of things that are different from each other.

For example:

You should try to eat a wide range of fruits and vegetables.

They had a wide range of different lamps, but none of them really appealed to me.

"A wide range..." sounds rather technical or scienticfic. People use it when explaining things.

You have to (do something)

This is a very straightforward way to give someone advice. You use this phrase when you definitely know more about something than the people who are listening:

A: I've never eaten that before. Do you eat it raw?

B: No, you have to cook it.

The bottom line is that you have to reduce your calorie intake to lose weight.

You can also use "You have to ___" when you're excited about something and you want to share it:

You have to try this! It's delicious!

If you use "You have to ___" to share an opinion, you might come across as rude. For example, don't use this phrase when giving friends advice about their relationships, job, etc.