Inversions occur in sentences where certain words or phrases are placed at the beginning to emphasize them. This includes negative words, expressions with "only", phrases with "so", and expressions of place or order. When these occur at the start of a sentence, the subject and verb are inverted, with an auxiliary used if the main verb is not "to be" or "to have". Inversions are used to highlight specific information or contrast.

1. INVERSIONS

2.  This type of sentences uses question word
order though the sentence is not a
question.
 The question word order implies the use of
an auxiliary if the main verb is not to be or
have; and if the sentence is Simple Present
or Simple Past.
Eg: Rarely do I meet foreigners in my
hometown.

3. When are inversions used?
 When the negative or emphatic words listed
below are placed at the beggining of a clause:
Eg:
Well do I remember the night I found out the thruth.
Not even once was he at home.
Seldom have I heard such beautiful music.
Not only did the company lose profits, but it also had to
lay odd workers.
No sooner had I left the building than my cell phone rang.

4.  When the following expressions
beginning with Only occur at the
beginning of a sentence:
Eg:
 Only once should you press the button.
 Only recently did he retire.
 Only in an emergency should you ring
this number.

5.  When the following expressions beginning with
Only occur at the beginning of a sentence.
With these expressions, the subject and the
verb of the second clause are inverted.
Eg:
 Only because you are my sister, are you
allowed to wear my skirt.
 Only after finishing Homework, is she going out
to play.
 Not until I find his office phone number will I be
able to contact him.

6.  When clauses beginning with so + adj or
so + adv occur at the begining of a
sentence
Eg:
So rare is this medal that it belong to a
museum.
So hard did he try that he deserved to win.

7.  When clauses beginning with expressions
of place or order occur at the beginning of
the sentence. In these cases, only the
subject and the verb are inverted; no
auxiliaries ae used.
Eg:
Opposite the bank is the park.
Off the coast of Punta del Este lies the Isla
Gorriti
First came my parents, then came my
siblings.