Clarifying the Use of When vs. Which in Sentence Construction

The proper use of English sentence structure, particularly in the use of relative pronouns like 'when' and 'which,' can significantly affect the clarity and coherence of a sentence. This article delves into the nuances of when to use 'when' and 'which' to ensure your sentences are clear, grammatically correct, and effectively convey the intended meaning.

Understanding the Use of 'When' and 'Which'

Latin has a distiction between 'quum' and 'quod,' translating roughly to 'whenever' and 'whereas,' respectively. In English, although we no longer have a sharp distinction between these, the use of 'when' and 'which' still carries subtle differences that can affect the meaning and flow of a sentence.

When - Emphasizing Time

The term 'when' is used to specify the time at which something occurs. It can be a key word in a sentence if the timing is an important element of the event being described. Here’s an example:

In 1983 Graham Greene travelled to Mexico when I met him.

In this sentence, 'when' is used to indicate the time at which the meeting occurred. It places emphasis on the year 1983 as the moment when the meeting took place. This sentence would be appropriate if you want to stress the timing of the meeting.

Which - Emphasizing Place or Object

On the other hand, 'which' is used to refer to a specific object or place. It can act as a relative pronoun, typically appearing in a non-defining clause. For example:

In this sentence, 'which is where I met him' means 'Mexico is where I met him.' This construction emphasizes the place, which, in this case, is Mexico.

Here’s an example sentence using 'which':

"Graham Greene travelled to Mexico in 1983 which is when I met him."

In this sentence, 'which' is pointing back to the place (Mexico) and emphasizing where the meeting happened. The timing (1983) is recast as an additional detail provided by the relative clause.

Clarifying Sentence Constructs

Why Your Original Sentence Was Correct, but Could Be Improved

Based on the original sentence: 'In 1983 Graham Greene travelled to Mexico when is where I met him.'

Your original sentence was technically correct in its use of 'which,' but could be improved in clarity and grammatical correctness. Here's why:

1. Proper Use of 'When': If you want to emphasize the time, you should use 'when' correctly by keeping it consistent with the past tense of the main clause (travelled) and rephrasing the sentence. For example:

In 1983 Graham Greene was travelling to Mexico when I met him.

2. Correct Use of 'Which': Given that 'which' refers to the place, you should use it correctly. For instance:

Graham Greene travelled to Mexico in 1983 which is when I met him.

3. Consistency in Tense: Ensure that the tenses match. Using 'was travelling' aligns with the past tense of 'travelled,' making the sentence more coherent.

Handling Commas and Sentence Spacing

Regarding the use of spaces before commas, it’s important to note that pasing spaces before commas can make your writing look unprofessional. Commas should be used meticulously, and spaces around them should be consistent with your chosen style guide, such as the Chicago Manual of Style or the APA.

Here is an example sentence corrected for proper comma use and spacing:

In 1983, Graham Greene travelled to Mexico when I met him.

Note: The original sentence mistake highlighted the importance of consistent and professional writing practices.

Final Thoughts

Both 'when' and 'which' have their unique roles in sentence construction. When you need to emphasize time, use 'when.' When you need to clarify a place or an object, use 'which.' Always ensure that your sentence structure and tense are consistent to avoid confusion and ensure that your writing is clear and effective.