TOEFL Mini-test (Skills 15-19)

1. Choose the correct phrase: Potassium reacts when ___ with other elements

Does it combine

It combines

In combining

Combination

“It combines” is correct because the clause requires a subject and verb in normal order. Other options either use incorrect inversion or lack a verb. Maintaining correct clause structure ensures clarity in scientific and descriptive sentences.

Explanation

“It combines” is correct because the clause requires a subject and verb in normal order. Other options either use incorrect inversion or lack a verb. Maintaining correct clause structure ensures clarity in scientific and descriptive sentences.

2. Choose the correct phrase: Rarely ___ located near city lights or at lower elevations

Observatories are

Are

In the observatories

Are observatories

“Are observatories” is correct because sentences beginning with negative adverbs like “rarely” require subject-verb inversion. The verb must come before the subject. Other options either lack inversion or are incomplete. Proper inversion ensures grammatical correctness and is essential in formal English structures involving negative adverbs.

Explanation

“Are observatories” is correct because sentences beginning with negative adverbs like “rarely” require subject-verb inversion. The verb must come before the subject. Other options either lack inversion or are incomplete. Proper inversion ensures grammatical correctness and is essential in formal English structures involving negative adverbs.

3. Choose the correct phrase: There are many reasons why ___ around the world

Diets differ

Do diets differ

Are diets different

To differ diets

“Diets differ” is correct because the clause requires a normal subject-verb order after “why.” Inversion is not needed in indirect questions. Other options incorrectly apply inversion or use incorrect forms. Maintaining correct clause structure ensures clarity and grammatical accuracy in complex sentences.

Explanation

“Diets differ” is correct because the clause requires a normal subject-verb order after “why.” Inversion is not needed in indirect questions. Other options incorrectly apply inversion or use incorrect forms. Maintaining correct clause structure ensures clarity and grammatical accuracy in complex sentences.

4. Choose the correct phrase: Nowhere ___ more distorted than in this industry

That figures are

Figures are

Are figures

Figures

“Are figures” is correct because sentences starting with “nowhere” require inversion. The verb must precede the subject. Other options either lack inversion or are incomplete. This structure emphasizes the negative condition and maintains proper grammatical form.

Explanation

“Are figures” is correct because sentences starting with “nowhere” require inversion. The verb must precede the subject. Other options either lack inversion or are incomplete. This structure emphasizes the negative condition and maintains proper grammatical form.

5. Choose the correct phrase: Were ___ millions each year, the coastline would change rapidly

The agency not spending

The agency not spend

The agency does not spend

Not spending the agency

“The agency not spending” correctly completes a conditional inversion structure beginning with “Were.” This form replaces “If the agency were not spending.” Other options use incorrect verb forms or structure. Understanding conditional inversion is essential for advanced grammar accuracy.

Explanation

“The agency not spending” correctly completes a conditional inversion structure beginning with “Were.” This form replaces “If the agency were not spending.” Other options use incorrect verb forms or structure. Understanding conditional inversion is essential for advanced grammar accuracy.

6. Choose the correct phrase: Only briefly ___ run at full speed

Cheetahs

Do cheetahs

That cheetahs can

Can

“Do cheetahs” is correct because “only” at the beginning triggers inversion. The auxiliary verb must precede the subject. Other options lack inversion or proper structure. This rule is essential for sentences starting with limiting or negative expressions.

Explanation

“Do cheetahs” is correct because “only” at the beginning triggers inversion. The auxiliary verb must precede the subject. Other options lack inversion or proper structure. This rule is essential for sentences starting with limiting or negative expressions.

7. Choose the correct phrase: Located behind ___ the tear glands

Each eyelid

Is each eyelid

Are each eyelid

Each eyelid which is

“Are each eyelid” is correct because the sentence begins with a location phrase, requiring inversion. The verb precedes the subject. Other options either lack a verb or use incorrect structure. Inversion is necessary to maintain grammatical correctness in such constructions.

Explanation

“Are each eyelid” is correct because the sentence begins with a location phrase, requiring inversion. The verb precedes the subject. Other options either lack a verb or use incorrect structure. Inversion is necessary to maintain grammatical correctness in such constructions.

8. Choose the correct phrase: The park is twice as large ___ Monaco

As

Is the

As is

As is the

“As is the” correctly completes the comparison using inversion. In formal comparisons, inversion is used after “as.” Other options either lack structure or omit necessary words. Proper comparison structures ensure clarity and grammatical correctness.

Explanation

“As is the” correctly completes the comparison using inversion. In formal comparisons, inversion is used after “as.” Other options either lack structure or omit necessary words. Proper comparison structures ensure clarity and grammatical correctness.

9. Choose the correct phrase: ___ test positive, the entire batch must be discarded

Should samples

If samples

If samples are

Samples should

“Should samples” correctly forms a conditional inversion replacing “If samples should.” This is a formal structure used in advanced English. Other options either lack inversion or do not match verb structure. Proper use of conditional inversion improves sentence sophistication.

Explanation

“Should samples” correctly forms a conditional inversion replacing “If samples should.” This is a formal structure used in advanced English. Other options either lack inversion or do not match verb structure. Proper use of conditional inversion improves sentence sophistication.

10. Choose the correct phrase: This topic will not be covered, ___ discussed

Trade unions will not

Nor trade unions will

Nor will trade unions

Neither trade unions will

“Nor will trade unions” is correct because “nor” requires inversion in the second clause. The auxiliary verb must come before the subject. Other options fail to apply inversion correctly. This structure is essential for maintaining parallel negative statements.

Explanation

“Nor will trade unions” is correct because “nor” requires inversion in the second clause. The auxiliary verb must come before the subject. Other options fail to apply inversion correctly. This structure is essential for maintaining parallel negative statements.