Preparation

One-word substitutions are important in written English and here is why:

• It make the writing crisp. Long sentences can make writing appear chunky and the one-word substitutions simplify sentences without changing their meaning
• By using one-word for a particular concept avoids confusion
• They add sophistication to the language
• They are useful for academic writing and competitive exams  

Here are some of the advantages of using one-word substitution in English language:

• They replace long sentences or phrase with one word and make the sentence concise
• One-word substitutions expresses ideas accurately with fewer words
• They help in expanding the knowledge and improves written, verbal, and communication skills
• Also, One-word substitutions reduces word count without making the sentence lose its meaning

When a conjunction is used to connect two independent clauses, a comma should be used before the conjunction.

To conclude, conjunctions are vital to constructing well-formed sentences in English. Whether writing or speaking, using the right conjunctions will help one convey their message more clearly and effectively.

Yes, it is acceptable to begin a sentence with conjunctions like "but," "and," or "because," but they should be used sparingly.

Yes, in informal speech or writing, conjunctions may sometimes be omitted for brevity.

Conjunctions are used to connect words, phrases, or clauses, allowing us to express more complex and meaningful thoughts in a simpler and smooth way.

If the statement is a universal truth or still relevant, verbs won't change typically. For example, the direct speech: "Water boils at 100 degrees," said the professor, and in the indirect speech: The professor said that water boils at 100 degrees. Being a fact, "boils" stays present. This keeps truths that are timeless or current—makes sense. 

Commands using the "to" verb structure shift to indirect speech: The direct speech is "Sit down!" shouted Dad. In the indirect speech version: Dad told me to sit down. When converting to indirect speech, the nature of the command softens, quotation marks disappear, and either "told" or "ordered" matches the strength of the command. Requests typically use the same to structure: "Please wait," translates to: He asked me to wait. 

To report questions, drop the question word order, if converting yes/no questions, invert using "if" or "whether," as well as changing the tense. Direct: "Are you ready?" asked Mia. Indirect: Mia asked if I was ready. The quotation marks are gone, and the sentence reports like a statement. For "wh-" questions, keep the "wh-" question word. Direct: "Where is it? Indirect: she asked where it was.