Explanations:The sentence in question is: "Bessemer discovered a knew way to make this strong, but lightweight, building material." The primary issue here is the misspelling of the word "knew." This is a common error because "knew" and "new" are homophones, meaning they sound the same but have different meanings and spellings.
The word "knew" is the past tense of the verb "know." It is used to indicate that someone had knowledge of something in the past. For example, "I knew the answer to the question." In contrast, "new" is an adjective that describes something that is recent, not previously existing, or not previously used. For example, "I bought a new car."
In the context of the sentence, the correct word to use is "new" because it refers to a novel or innovative method that Bessemer discovered. The sentence is discussing a discovery, and the method is described as a new way to make a building material, not something that Bessemer knew about.
It is important to understand the distinction between these homophones to avoid such errors in writing. The correct sentence would read: "Bessemer discovered a new way to make this strong, but lightweight, building material."
Other aspects of the sentence, such as the use of "discovered" and "this," are grammatically correct and do not require any changes. The word "discovered" is in the past tense, which is appropriate for discussing a historical event. The word "this" correctly refers to the singular noun "building material."
Homophones are a common source of spelling errors, and it is crucial to be aware of them to ensure clear and accurate communication. In competitive exams and standardized tests, such as the GRE, GMAT, TOEFL, and IELTS, correct spelling and usage of homophones are often tested to assess language proficiency.