助動詞位置

on no account是否定用詞，用來修飾述部時，放在第一個助動詞之後，如移到句首時，會造成句子要強制倒裝（助動詞隨之移到主詞之前）．

On no account should the mixture come near boiling

on no account = under no circumstances

If you say something should on no account be done, you are emphasizing that it should not be done under any cirsumstance.（on no account放在第一個助動詞之後）

... I could on no account agree to such a principle.
... on no account could I agree to such a principle.

2015-04-25 17:41:15 補充：
... I could agree to such a principle on no account.
這是另一個放no account的位置．

Inverse is concerned with in inverse proportion, eg:- when "could I "transposed to" I could", or aux.verb transposed to verb aux.

Inversion is altering the natural order of words:- Sorrow is sweet---->How sweet sorrow is;------A thief is He------.A thief He is.------eg:-Over me their occupied Central banners wave------->Their occupied Central banner wave over me. which is the natural order involved.

Reading full of fun in "M",you'll read the following(1)shake as in instruction by pouring food (2)Add sachet of flavouring (3)Close the gap (4)Shake them off to disappear by M's throwing into gabbage bin ? Or empty itself?This similie is comparable to the "Inversion two words " being disappeared as follows:-

on no account=under no circumstances
on no account could I agree to such a principle(e).----negation at beginning=Forced to Inversion=aux.subj=could I
I could on no account agree to such a principle(e)------put first aux v behind subj=I could
I could to such a principle on no account?----putting at end
I could on no account-----The main statement
I could not agree-------The main statement again
I disagree.In reverse proportion reversed
Inversion two words"could I " being disappeared.
The similie comparable established.