In the following question, four words are given, out of which one word is incorrectly spelt. Find the incorrectly spelt word.

Introduction / Context:
This spelling question again asks you to identify the single incorrectly spelt word from a group of four. Words for common objects like 'handkerchief' are often misspelt because of unusual letter order. Recognising the correct pattern is important for error spotting and accurate written communication in English.

Given Data / Assumptions:
- Options: 'Guidance', 'Ambassador', 'Handkercheif', 'Labourer'.
- Exactly one of these words does not match the standard dictionary spelling.

Concept / Approach:
The tricky word here is 'handkerchief'. Many learners misplace the 'ie' sequence and write 'handkercheif'. The correct spelling is h-a-n-d-k-e-r-c-h-i-e-f, where 'chief' appears at the end, not 'cheif'. The other words are correctly spelt: 'Guidance' (help or direction), 'Ambassador' (official representative of a country) and 'Labourer' (a person who does physical work). Therefore, we must select 'Handkercheif' as the incorrect form.

Step-by-Step Solution:
Step 1: Examine 'Guidance': this is the correct spelling used in phrases like 'career guidance' and 'moral guidance'. Step 2: Examine 'Ambassador': this word is correctly spelt with 'assa' in the middle, as in 'Indian ambassador'. Step 3: Examine 'Handkercheif': this looks suspicious because of the 'cheif' ending, which is a common error. Step 4: Recall the correct spelling 'Handkerchief': h-a-n-d-k-e-r-c-h-i-e-f, following the same 'chief' pattern as in 'chief'. Step 5: Examine 'Labourer': this is correctly spelt in British English with 'ou', meaning a person who does manual work.

Verification / Alternative check:
Compare 'handkercheif' with other words ending in 'chief': 'chief', 'mischief', 'handkerchief'. All have the 'i-e-f' sequence, not 'e-i-f'. Remembering the separate word 'chief' makes it easier to spot that 'cheif' is incorrect. The fact that 'Guidance', 'Ambassador' and 'Labourer' appear exactly as they do in textbooks and newspapers confirms that they are correctly spelt.

Why Other Options Are Wrong:
'Guidance' is correct and should not be confused with incorrect forms like 'guidence'. 'Ambassador' is correct and widely used in diplomacy and news reports. 'Labourer' is correct in British English spelling, which is the standard used in many exams; the American form 'laborer' is also correct but represents a different spelling standard, not an error in this context. Therefore, none of these can be chosen as the misspelt word.

Common Pitfalls:
The main trap is the very common typo 'cheif' instead of 'chief'. Many learners memorise words visually and may not notice the change. To avoid such mistakes, remember the simple rule 'i before e' in 'chief' and apply it to 'handkerchief' as 'handker + chief'. When you see 'Handkercheif', recognise that the vowels have been swapped and that this is the incorrect variant.

Final Answer:
The incorrectly spelt word is Handkercheif; the correct spelling is 'Handkerchief'.