Preparation

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.

Tenses tend to backshift in indirect speech; thus, present to past, past to past perfect. Direct: "I eat pizza," says Jack. Indirect: Jack said he had made pizza. This "backshift" is important as it indicates the action came before the speaker. Do not backshift tenses, however, with facts. For example, "the earth is round" remains "the earth is round."

To change a statement, just change the pronouns, change the tense (hence, “say” to “said, ” or “is” to “was”), and change the time words. E.g., direct: "I am tired," said Emma. Indirect: Emma said she was tired. Remove the quotation marks, use "that" to link the two sentences together, and position yourself in that of the author.

Subject plays a crucial role in letter writing, and while writing a letter, the candidate must write a very apt, creative, and short subject. For example, “Request for Scholarship Renewal” or “Complaint Regarding Water Supply.”

In competitive exams, just next to the question, the word count is written, however, most exams expect 150–200 words. Going beyond can cost marks and also consume a lot of time and in exams, a student needs to be time-constrained. Practice writing letters that are concise, focused, and within limits.