In the following English vocabulary question, four different words are given as options. Three of these words are spelled correctly in standard English, while one word is spelled incorrectly. Carefully identify and choose the incorrectly spelled word from the given alternatives.

Introduction / Context:
This question tests the candidate's command over English spelling and vocabulary. Competitive exams often ask such questions to check whether students can differentiate between correctly and incorrectly spelled words that look very similar. Here, four advanced vocabulary items are given, all of which might appear in formal writing. Only one option is wrongly spelled, and the task is to identify that incorrect spelling by recalling correct patterns of English word formation and common suffixes used in adjectives.

Given Data / Assumptions:
- Four words are given as options: Contemptous, Commemorate, Complaisant, and Conciliatory.
- Exactly one of these spellings is incorrect according to standard English usage.
- The question does not ask for meanings, but knowing the meaning sometimes helps recall the correct spelling.
- We assume standard modern British or international English spelling conventions.

Concept / Approach:
The core idea is to recognise typical English suffix patterns and how root words combine with them. Words like "commemorate", "complaisant", and "conciliatory" are common in written English and have fairly fixed spellings. The adjective formed from the noun "contempt" is "contemptuous" with the suffix "uous". Many learners confuse "uous" with "ous" because both occur in English adjectives, as in "curious" and "virtuous". Therefore, a careful comparison of memory, reading experience, and suffix rules helps in spotting the incorrect option.

Step-by-Step Solution:
Step 1: Examine option A, "Contemptous". The base noun is "contempt". The standard adjective derived from it is "contemptuous", not "contemptous". Step 2: Examine option B, "Commemorate". This word means to honour the memory of someone or something, and this spelling is widely accepted in dictionaries. Step 3: Examine option C, "Complaisant". This means obliging or willing to please, and "complaisant" is the correct spelling in standard English. Step 4: Examine option D, "Conciliatory". This adjective describes something that is intended to pacify or make peace, and this spelling is also standard and correct. Step 5: Since options B, C, and D match dictionary spellings, and option A does not, "Contemptous" must be the incorrectly spelled word.

Verification / Alternative check:
One can verify the reasoning by recalling phrases like "a contemptuous attitude" which frequently appear in books and articles. The adjective always has the extra "u" as in "tuous". Similarly, "commemorate" is seen in expressions like "to commemorate an event", "complaisant" appears in literary contexts, and "conciliatory measures" is a common collocation in news and academic writing. A quick mental cross check with these familiar phrases confirms that only option A deviates from the standard spelling pattern.

Why Other Options Are Wrong:
Here "wrong" means they are wrong as answers because they are actually correct spellings.
- "Commemorate" is correctly spelled and therefore cannot be the incorrect option.
- "Complaisant" is correctly spelled for the meaning "willing to please", so it is not the required answer.
- "Conciliatory" is correctly spelled and is a common adjective in formal English, so it is also not the answer.

Common Pitfalls:
Students often confuse similar looking suffixes such as "ous", "eous", and "uous". Because many adjectives end in "ous", candidates may assume that "contemptous" looks acceptable at first glance. Another common error is to rely purely on visual familiarity without consciously recalling root words like "contempt". Under exam pressure, test takers may rush and mark a correctly spelled word as wrong simply because they are less familiar with it. Careful reading and a calm comparison of each option with known patterns of English word formation help avoid these mistakes.

Final Answer:
The incorrectly spelled word is Contemptous, which should be spelled "contemptuous" in standard English.