In this sentence improvement question, the underlined phrase "departed for London" is to be evaluated in the sentence: Navinder and his wife departed for London by Air India yesterday. Choose the best alternative if improvement is needed.

Introduction / Context:
This question focuses on correct prepositional usage with the verb "depart" in a travel context. Many learners are unsure whether to say "depart to", "depart for", or "depart towards" when talking about journeys. The sentence given is "Navinder and his wife departed for London by Air India yesterday." You must decide whether the phrase "departed for London" is correct or if it should be replaced by another option.

Given Data / Assumptions:
- Original sentence: Navinder and his wife departed for London by Air India yesterday.- The underlined phrase is "departed for London".- Options suggest changing "for" to "to", "towards", "toward", or leaving it as it is (No improvement).- The intended meaning is that they left their current place and travelled to London.

Concept / Approach:
In standard English, the verb "depart" is commonly followed by the preposition "for" when indicating the destination: "depart for London", "depart for Delhi", "depart for New York". The pattern "depart to London" is not idiomatic, and "depart towards London" focuses on direction rather than describing the destination of a scheduled journey. Therefore, "depart for London" is the correct and natural collocation, and no change is required.

Step-by-Step Solution:
Step 1: Identify the verb-preposition combination in the original sentence: "departed for London".Step 2: Recall typical announcements: "The train will depart for Mumbai", "The flight departs for Singapore at six."Step 3: Compare this with "depart to London", which sounds unnatural in modern English.Step 4: Consider "depart towards London", which emphasises direction and is rarely used in scheduled travel contexts.Step 5: Observe that the original structure matches standard usage in airline and railway English.Step 6: Conclude that no grammatical or idiomatic improvement is needed.

Verification / Alternative check:
You can verify by thinking of common travel sentences: "They departed for Paris last night", "The flight departed for Dubai on time", "The bus will depart for the capital at noon". Native speakers consistently use "for" with "depart" when specifying the destination. Dictionaries also give example sentences with "depart for" plus the place name. This repeated pattern confirms that the original phrase is already correct.

Why Other Options Are Wrong:
Option "to": "Depart to London" is not idiomatic; we say "go to London" but "depart for London".Option "towards": Suggests movement in the direction of London but does not match the typical travel announcement style and can sound unusual here.Option "toward": Similar issue as "towards"; it describes direction, not the standard collocation for a planned journey destination.

Common Pitfalls:
Students may overgeneralise the use of "to" after verbs of movement, assuming that any verb implying motion must be followed by "to" plus a place. However, English has fixed verb-preposition combinations, and "depart for" is one of them. Another pitfall is thinking that "towards" is more formal or advanced, but formality does not make it correct. It is more important to remember collocations as they are naturally used in real travel announcements and written schedules.

Final Answer:
The phrase "departed for London" is already correct, so the best choice is No improvement.