stuff

"Stuff" can mean almost any physical items or material.

It's similar to the word "things", but "things" are countable and "stuff" is not. So "stuff" is better to use when you're talking about a group of things that are different from each other - different sizes, shapes, etc.

"Stuff" is especially used to refer to things that you buy or own:

There's a good chance that you'll end up buying a lot of stuff while you're there.

I'll go pick up all the stuff we need.

Excuse me. Would you mind watching over my stuff for me for just a minute?

But "stuff" can also mean "topics" or "ideas", like in this example:

We have a lot of stuff to talk about.

hang out with (someone)

"Hanging out with" someone means spending time together for fun. When you "hang out" with someone, you talk, eat, drink, laugh, watch movies, play games, etc.

This expression is slightly casual. You use it like this:

I hung out with Kim a few days ago.

Let's hang out sometime soon.

miss (doing something)

Use "miss ___ing" if you used to do something, and now you don't, but you wish you still did:

I miss hanging out with my friends from college.

You can talk about someone else's feelings as well:

I think my dad misses going to work every day now that he's retired.

geek out (about/over something)

The phrasal verb "geek out" means to get really excited about the small details of a subject. Things that people sometimes "geek out" over include:

• computers
• comic books
• sports statistics

You can explain what someone is interested in with "geek out over ___":

I used to geek out over music equipment.

People also sometimes say "geek out about ___":

Math is a subject that I can really geek out about.

When people "geek out" together in a conversation or an online chat, you use "with":

I love it when I can geek out with other baseball fans.