Everyday English expressions: cool, my bad, no worries and more
Short answer: Everyday expressions such as “cool”, “awesome”, “my bad” and “no worries” are informal words and phrases that people use all the time. They are fine with friends and in casual messages, but plain words are better in formal writing.
What do these expressions mean?
| Expression | Meaning | Example |
|---|---|---|
| Cool | Very good; great | I like your new backpack. It's really cool. |
| Awesome | Very good; amazing | The view from the top was awesome. |
| Dude | An informal way to call a friend or person | Dude, you left your keys on the table. |
| What's up? | A friendly way to say hello or ask what is happening | Hi Sam! What's up? |
| Chill / Chill out | Relax; stay calm | Just chill. We have plenty of time. |
| Hang out | To spend free time with friends | We hang out at the park after work. |
| My bad | I made a mistake. Sorry | My bad, I sent you the wrong file. |
| No worries / No biggie | It is okay. Do not worry | Thanks for waiting. — No worries! |
| Bummer | Something bad or disappointing has happened | Bummer, the shop is closed today. |
| Lame | Not good or interesting (can sound rude) | The ending of that story was lame. |
| Couch potato | Someone who spends a lot of time sitting and watching TV | On rainy Sundays I turn into a couch potato. |
| Vibe / Vibes | The feeling you get from a place or person | This place has a calm vibe. |
When do you use everyday expressions?
- To say that something is good: “cool”, “awesome”.
- To greet someone casually: “What's up?”
- To say sorry or to answer a sorry: “My bad”, “No worries”.
- To talk about free time: “hang out”, “chill”.
Are they formal or informal?
They are informal. Use them with friends, family and classmates, in casual chat and in messages. In an email to a manager or in an essay, choose plain words: “very good”, “I am sorry for my mistake”, “it is no problem”.
Common mistakes with everyday expressions
- “Lame” can sound rude, so do not use it about a person.
- “Dude” is for a friend. Do not use it with someone you have just met.
- “Chill” means relax or stay calm. “Chill out” means the same.
- “My bad” is a casual way to say you made a mistake. For an important mistake, say a full “I'm sorry”.
Similar expressions
“No worries” and “no biggie” both mean it is okay. “Cool” and “awesome” both say that something is good, and “awesome” is stronger.
More idioms
- English idioms: meanings and examples (all groups)
- Idioms about everyday life, time and weather: meanings and examples
- Idioms about money: meanings and examples
- Idioms about feelings: meanings and examples
Questions
What does “my bad” mean?
It means “I made a mistake, sorry”. It is informal. For example, “My bad, I sent you the wrong file.”
What does “no worries” mean?
It means it is okay, do not worry. People say it after someone says sorry or thanks.
What does “hang out” mean?
It means to spend free time with friends, often without a plan.
What is a “couch potato”?
A couch potato is someone who spends a lot of time sitting and watching TV.
Is “awesome” formal?
No. “Awesome” is informal. It is fine in speech and casual messages. In formal writing, use “excellent” or “very good”.
Part of the English idioms guide in the 💬 Idioms tool.
Written for English learners by the English for Fun team. How we write our lessons · Last updated 2026-11-05.