The Everyday Slang Toolkit

These expressions are safe in almost any informal setting:

• "Cool" — the universal agreement word that never goes out of style
• "No worries" — a relaxed way to say "you're welcome" or "it's fine"
• "My bad" — a casual apology for small mistakes
• "Gotcha" — "I understand" in one punchy word
• "Gonna / wanna / gotta" — spoken contractions that signal you are comfortable in English

Notice that none of these words are crude, controversial, or generation-specific.