English Grammar — Spot the error (choose the incorrect part; select 'No error' if the sentence is correct). Sentence parts: A) He loosened his temper B) whenever he knows C) things do not take place D) as per his planning. E) No error

Introduction / Context:
The item examines idiomatic usage and tense consistency in habitual vs. past narratives. The phrase “loosened his temper” is non-idiomatic; standard English uses “lost his temper.”

Given Data / Assumptions:

• Segment A: “He loosened his temper.”
• Segment B: Present tense “knows” mixed with past “loosened.”
• Segments C and D are structurally acceptable though D is slightly formal.

Concept / Approach:
Idioms must be used as established: the fixed expression is “lose one’s temper.” Additionally, maintain consistent tense. If the sentence describes a habitual reaction, simple present is preferable: “He loses his temper whenever he knows …”

Step-by-Step Solution:

Verification / Alternative check:
Test the idiom in standard corpora or by substitution: “He lost his temper …” is widely attested; “loosened his temper” is not.

Why Other Options Are Wrong:

• B: Tense mismatch exists, but the primary error targeted is the idiom in A in typical single-error questions.
• C: Grammatically acceptable clause.
• D: Formal but grammatical; not the key error.
• E: Not applicable since A has an error.

Common Pitfalls:
Inventing near-idioms like “loosened his temper” leads to awkwardness. Also, mixing past and present tenses in a habitual statement confuses time reference. Correct both when revising.

Final Answer:
A) He loosened his temper