What part of speech is “thank-you”

interjections are words or phrases that express strong emotion or sudden exclamations. They are often standalone and don't grammatically relate to the rest of the sentence.

'thank you' as an interjection is used to express gratitude or appreciation towards someone for something they've done or provided.

Thank you for holding the door for me.

Thank you! I've been looking for my keys everywhere.

I can't believe you did all this for me. Thank you.

'Thank you' can be followed by various extensions, such as 'very much' or 'so much' to add emphasis to the gratitude. It can also be followed by a specific reason for the gratitude, e.g., 'Thank you for your help.' Avoid overusing 'thank you' in situations where it may not be necessary, as it can come off as insincere.