In the following question, four spellings of a comparative form are given, out of which only one is correct. Read them carefully and select the correctly spelt word meaning “more full of froth or foam.”

Introduction / Context:
This spelling question asks for the correct superlative form of “frothy,” which describes something full of small bubbles, such as coffee, waves, or soap. The learner must pick the correct spelling among four similar looking options. Such questions strengthen understanding of standard rules for forming comparative and superlative adjectives in English.

Given Data / Assumptions:
- Base adjective: “frothy”- Intended degree: superlative form, equivalent to “most frothy”- Options: “frothyiest,” “frotheist,” “frothyeist,” and “frothiest.”

Concept / Approach:
When forming the comparative and superlative of adjectives ending in “y,” English usually changes the “y” to “i” and adds “-er” for comparative and “-est” for superlative. For example, “happy” becomes “happier” and “happiest,” “busy” becomes “busier” and “busiest.” Similarly, “frothy” becomes “frothier” and “frothiest.” The correct spelling will therefore follow this pattern and should be “frothiest.”

Step-by-Step Solution:
Start with the base word: f r o t h y.For the superlative, drop the “y” and replace it with “i e s t.” This gives f r o t h i e s t.Option D, “frothiest,” matches exactly this pattern and is consistent with standard rules and usage.Option A, “frothyiest,” keeps the “y” and then adds “iest,” resulting in an extra letter and an incorrect formation.Option B, “frotheist,” replaces “y” with “e,” which does not reflect the “y” to “i” rule and also changes pronunciation.Option C, “frothyeist,” again keeps both “y” and “e,” creating an awkward and incorrect cluster “yei.”

Verification / Alternative check:
Compare with similar adjectives. “Healthy” becomes “healthier” and “healthiest,” not “healthyiest.” “Wealthy” becomes “wealthier” and “wealthiest.” The consistent pattern is “y” to “i” before adding “est.” Using “frothiest” in a sentence such as “This is the frothiest cappuccino I have ever had” also confirms that it looks and sounds correct in context.

Why Other Options Are Wrong:
“Frothyiest” is wrong because it includes both “y” and “i,” violating the normal spelling rule and creating an unnecessary extra letter.“Frotheist” is wrong because it loses the “y” but does not replace it correctly with “i,” giving a distorted vowel pattern.“Frothyeist” is wrong because it contains an awkward “yei” sequence that does not correspond to any standard English rule.

Common Pitfalls:
Students sometimes overcomplicate patterns when they see several very similar options. Remember that the general rule for adjectives ending in “y” preceded by a consonant is simple: change “y” to “i” and add “est.” Sticking to this rule prevents confusion in many similar cases.

Final Answer:
The correctly spelt word is frothiest.