Interacting informally, reacting, expressing interest, sympathy, surprise, etc.

Informal interaction covers short phrases and reactions we use in casual conversation to show interest, surprise, sympathy, agreement, or excitement. These expressions are useful in spoken exchanges, instant messages, and informal emails with colleagues or clients you know well.

• Use short, natural phrases to react quickly (e.g., “Really?”, “No way!”, “That’s great!”).
• Match your tone to the situation: sympathetic when someone shares bad news, enthusiastic for good news.
• Be aware of register: some informal expressions are fine in chat but not in formal reports or external client emails.

Choose a reaction that fits the situation and the relationship with the listener:

• Positive news → be enthusiastic (e.g., “That's fantastic!”, “Congratulations!”).
• Bad news → show sympathy and offer help (e.g., “I'm sorry to hear that.”).
• Surprise or disbelief → use short interjections (e.g., “Really?”, “No way!”).
• Curiosity → prompt more information (e.g., “Interesting — tell me more.”).

In written, professional messages prefer polite phrasing; save very informal interjections for chat or face-to-face.

Watch out for these universal errors when using informal reactions:

• Using overly informal expressions in formal contexts (e.g., emails to external clients).
• Repeating the same short interjection too often, which can sound insincere.
• Choosing an inappropriate reaction (e.g., saying 'That's great' to bad news).
• Overusing fillers (e.g., 'like', 'you know') that reduce clarity.

Pause and choose a phrase that matches both the content and the relationship.