INVERSION SENTENCES

nversion refers to an irregular verb placement form: Use of Question Form
In this case, the question form (auxiliary + subject + main verb) takes the place of the standard positive sentence structure (i.e. He goes to work every day):
Examples
Not only do I enjoy classical music, but I also have a season ticket to the symphony.
Seldom has the boss been so upset!
In this case, the question form is substituted for standard sentence structure in a statement. Generally, an inversion is used to stress the uniqueness of an event and begins with a negative.
Negative Adverbials
Time expressions: never, rarely, seldom
These time expressions are used with a perfect form or with modals and often include comparatives:
Examples
Never have I been more insulted!
Seldom has he seen anything stranger.
Time expressions: hardly, barely, no sooner, or scarcely
These time expressions are used when a there are a succession of events in the past.
Examples
Scarcely had I got out of bed when the doorbell rang.
No sooner had he finished dinner, when she walked in the door.
After 'Only' Expressions such as 'only after', 'only when', 'only then', etc.
'Only' is used with a time expression.
Examples
Only then did I understand the problem.
Only after understanding the situation does the teacher make a comment.
After 'Little'
'Little' is used in a negative sense.
Examples
Little did he understand the situation.
Little have I read concerning nanotechnology.
Inversion after 'So', 'Such', and 'That'
'So'
'So + adjective ... that' combines with the verb 'to be'.
Examples
So strange was the situation that I couldn't sleep.
So difficult is the test that students need three months to prepare.
'Such'
'So + to be + noun ... (that)':
Examples
Such is the moment that all greats traverse.
Such is the stuff of dreams.
Inverted Conditional Forms
Sometimes conditional forms are inverted as a means of sounding more formal. In this case, the conditional 'if' is dropped and the inverted forms takes the place of the 'if clause'.
Examples
Had he understood the problem, he wouldn't have committed those mistakes.
Should he decide to come, please telephone
When to Invert the Subject and Verb:

1. Questions
2. Negatives
3. (Necessary) Prepositional Phrases of Place
4. Conditionals
5. Comparisons

1. Questions

He is a doctor.He ate an apple.

Is he a doctor?Did he eat an apple?

(Direct inversion)(With ?do?)

2. Negatives

He is a doctor.He ate an apple.

Not only is he a doctor, (but) he is also a millionaire.Not only did he eat an apple, (but) he also ate an orange.

3. Prepositional Phrases of Place (Necessary)

On the table is a book.

On the table (there) is a book.

The prepositional phrase is necessary here, because without it, the sentence would be incomplete: (?is a book?is not a complete sentence.) Inversion is necessary.

At the restaurant, the food was too spicy.

(inversion is not necessary)

Without the prepositional phrase, the sentence ? the food was too spicy ?is still complete. This structure is typically used with linking verbs (be, appear, seem, etc.) or words that function as linking verbs.

In the doorway appeared two strangers. On the table lies my textbook. In the kitchen, he ate an apple.

In the doorway were two strangers. On the table is my textbook.(Action verb: no inversion necessary.)

4. In some situations, the conditional if is omitted and an inversion is used in its place. (Only with verbs, were, should or had.) Note the following examples:
If I were a doctor, I would be rich. Were I a doctor, I would be rich. If I had taken the subway, I would have arrived on time. Had I taken the subway, I would have arrived on time. If you should have any questions, please feel free to contact me. Should you have any questions, please feel free to contact me. If I had known you were coming, I would have baked a cake. Had I known you were coming, I would have baked a cake. If I go to Chicago, I will visit my grandmother. XX Go I to Chicago, I will visit my grandmother. If I have enough money, I will buy a horse. XX Have I enough money, I will buy a horse.
5. Comparisons with than may also be inverted, but the inversion is optional. Note the following examples.
He has more marbles than John does. He has more marbles than does John. He has more marbles than John. (informal okay.)
**Be careful. On the TOEFL, when comparisons are used, sometimes important words are left out or in error, thereby requiring only one of the possible options.
She loves her cat more than Jim. She loves her cat more than she loves Jim. She loves her cat more than Jim loves her cat./more than Jim does. My dog is smarter than Jack. My dog is smarter than Jack's. My dog is smarter than Jack's dog. My dog is smarter than that of Jack. My classes are more challenging than those of Mindy.