Sentence structure: After what you did last night it's over.

[Tjef]

How would you describe the structure of this sentence?

'After what you did last night it's over.'

Does it need a comma after 'night'? Is 'after what you did last night' a noun phrase?

Please help I'm really confused.

[Inga]

The sentence sounds Russian to me. I don't think you need a comma here. But I think it's a noun clause (after prepositions).
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I am an incurable optimist.

[Yankee]

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I'd add the comma if only to make the sentence easier to read. I'd also add an exclamation point since that sentence would usually be said with a lot of emotion and/or emphasis:

After what you did last night, it's over!
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