What does 'Not once did they finish a job properly.' mean here please?

[shinji002]

Dear Mr Answer
Not once did they finish a job properly.


why it gets "did" before "they"? Do you have any grammar ref on this form:"Not once did they finish a job properly. "?

[Kraken]

They never finished a job properly (not even once).

It's called inversion

Inversion not only can be used to form questions and conditional sentences. Also, we can use inversion for emphasis.

* Little did she know how much work was left.
* On no account must you sleep at school.
* Never should you remember who's your boss.
* Only then can you belong to me.
* Here comes the sun.

All these structure are rather literary, which means there are more likely to appear in books.

More informantion here:
Inversion of the verb after certain adverbs

[BobK]

They never finished a job properly (not even once).

It's called inversion

Inversion not only can be used to form questions and conditional sentences. Also, we can use inversion for emphasis.

* Little did she know how much work was left.
Teacher's version (TV): "Little do you know how much background reading you'll have to do when you get to A-level."
* On no account must you sleep at school.
TV: 'On no account are you to copy from Wikipedia."
* Never should you remember [forget?] who's your boss.
TV: Never again are you to give me such shoddy work.
* Only then can you belong to me.
TV: Only then can you be said to have mastered the subject.
* Here comes the sun.
TV: There goes the bell.


All these structure are rather literary, which means there are more likely to appear in books.

...

. But not just in books. As my rewrites of your examples show, this form is very popular with teachers - anyone who has to speak in front of people in an authoritarian way.

b

[BobK]

PS
And here's a Teacher's Version using 'Not once' (as in the original post): "Not once have I had a word of thanks for taking the after-school rugby club."

b

[shinji002]

thank you all.