Analyzing the Grammar Error in Compound Nouns

The question asks us to identify the part of the sentence "Mother-in-laws (A)/ are (B) / a nuisance.(C) / No Error (D)" that contains a grammatical error.

Let's examine each part of the sentence:

• Part (A): "Mother-in-laws"
• Part (B): "are"
• Part (C): "a nuisance."

The subject of the sentence is the compound noun "mother-in-law". Compound nouns formed with prepositions, like "mother-in-law", "sister-in-law", "father-in-law", "commander-in-chief", etc., are pluralized by adding 's' to the main noun (usually the first word), not the last word.

Let's look at the correct and incorrect plural forms:

• Singular: mother-in-law
• Incorrect Plural: mother-in-laws
• Correct Plural: mothers-in-law

In the given sentence, part (A) uses the incorrect plural form "Mother-in-laws". The correct form should be "Mothers-in-law".

Part (B) uses the verb "are". If the subject were the correct plural "Mothers-in-law", the plural verb "are" would be appropriate, agreeing in number with the subject. So, part (B) is correct assuming the subject is intended to be plural.

Part (C) "a nuisance" is a predicate nominative describing the subject. "a nuisance" is singular. This might seem contradictory if the subject is plural "Mothers-in-law". However, "a nuisance" here can refer to each individual within the group or the group collectively as a concept (similar to saying "Americans are a free people"). While slightly awkward phrasing, it is grammatically permissible in some contexts and the primary error is in the pluralization of the subject noun itself.

Therefore, the most significant and clear error is in part (A), where the compound noun is incorrectly pluralized.

The correct sentence should be: "Mothers-in-law are a nuisance."

Revision Table: Compound Noun Pluralization

Additional Information on Compound Nouns

Compound nouns are nouns made up of two or more words. These words can be combined in various ways:

• As one word: keyboard, toothpaste, bedroom
• Hyphenated: mother-in-law, commander-in-chief, well-being
• As separate words: bus stop, living room, attorney general

The pluralization of compound nouns depends on their structure:

• For compound nouns written as one word, the plural is usually formed by adding -s or -es to the end (e.g., keyboards, toothpastes, bedrooms).
• For hyphenated or separate compound nouns where a noun is the main part, the plural is usually formed by adding -s or -es to the main noun (which isn't always the last word).
  • Examples: mothers-in-law, commanders-in-chief, attorneys general.
• If the compound noun doesn't contain a noun, or if the last word is the most significant, the plural is formed by adding -s or -es to the end.
  • Examples: looker-ons (from looker-on), stand-ins (from stand-in), break-ins (from break-in), forget-me-nots (from forget-me-not).
• Some compound nouns have irregular plurals (e.g., man-of-war → men-of-war).

Understanding how to correctly pluralize different types of compound nouns is important for grammatical accuracy.