Understanding Grammar Errors in Sentence Correction

Let's analyze the given sentence to identify the grammatical error. The sentence is:

"Once considered ninth planet of the solar system, (a) / Pluto is today listed as the (b) / largest dwarf planet of the solar system. (c) / No error (d)"

We need to examine each underlined part for potential errors.

Analyzing Part (a): "Once considered ninth planet of the solar system,"

This part describes Pluto's former status. The phrase "ninth planet" uses an ordinal number ('ninth') to specify the position of the planet in a sequence. In English grammar, when referring to a specific item in a sequence using an ordinal number, we typically use the definite article 'the' before the ordinal number.

Consider these examples:

• He finished the first lap.
• This is the second time I've visited.
• She lives on the third floor.

In the phrase "ninth planet of the solar system," 'ninth planet' refers to the specific planet that held the ninth position. Therefore, it should be preceded by the definite article 'the'.

The phrase should correctly be "Once considered the ninth planet of the solar system,".

Thus, there is an error in part (a) due to the missing article 'the'.

Analyzing Part (b): "Pluto is today listed as the"

This part uses the passive voice ("is listed") which is grammatically correct here. "Today" is an adverb modifying "is listed". "As the" is used correctly to introduce what Pluto is listed as.

This part appears to be grammatically sound.

Analyzing Part (c): "largest dwarf planet of the solar system."

This part uses the superlative degree of the adjective ('largest') followed by a noun ('dwarf planet'). Superlative adjectives are almost always preceded by the definite article 'the', which is correctly used here ("the largest dwarf planet"). The phrase "of the solar system" correctly modifies "dwarf planet".

This part also appears to be grammatically sound.

Conclusion on the Grammar Error

Based on the analysis, the error lies in part (a) where the definite article 'the' is missing before the ordinal number 'ninth'.

The corrected sentence would read:

"Once considered the ninth planet of the solar system, Pluto is today listed as the largest dwarf planet of the solar system."

Therefore, the part with the error is (a).

Revision Table: Key Grammar Concepts

Reviewing key concepts related to this question helps reinforce understanding.

• Articles: 'a', 'an', and 'the'. 'The' is a definite article used for specific nouns.
• Ordinal Numbers: Numbers indicating position in a sequence (first, second, ninth, tenth, etc.).
• Using 'The' with Ordinal Numbers: Generally, 'the' is used before ordinal numbers when they refer to a specific item or position (e.g., the first chapter, the seventh day).
• Superlative Adjectives: Adjectives indicating the highest degree of a quality (tallest, largest, most beautiful). They are usually preceded by 'the' (e.g., the tallest building).

Additional Information: Articles and Ordinal Numbers

Let's delve a bit deeper into the use of articles, specifically 'the', with ordinal numbers. The rule is quite consistent: use 'the' before an ordinal number when it functions as an adjective modifying a noun, and that noun is specific or understood from the context.

Examples:

• This is the fifth time I have called. ('fifth time' refers to a specific occurrence in a sequence)
• Read the second paragraph. ('second paragraph' refers to a specific paragraph)
• He was the last person to arrive. ('last' functions like an ordinal number here)

There are some exceptions, mainly in fixed phrases or when the ordinal number functions differently (e.g., in lists or titles where articles might be omitted for brevity or style, but these are less common in standard descriptive prose).

In the sentence about Pluto, "ninth planet" is a specific historical designation for its position, hence requiring 'the'.