1. "but on YouTube, but" → "but on YouTube [space]"
The double use of "but" creates a redundant and ungrammatical construction. In English, when contrasting two elements (TV vs. YouTube), a single "but" is sufficient. The second "but" is removed to create a more concise and grammatically correct sentence structure.

1,2. "request business owners and doctors to provide loans" → "request loans or investments from business owners and doctors"
The original structure was OK, but less natural. This follows the more natural English pattern: "request something from someone" rather than "request someone to provide something."

3,4. "the doctor whom" → "a doctor who"
Two corrections here:
- The definite article "the" implies a previously mentioned specific doctor, but this is the first mention, so the indefinite article "a" is appropriate.
- "Whom" sounds too formal in this context.

5,6. "to the applicant who was aiming to pass the university's medical school" → "to an aspiring medical student who was preparing to enter medical school"
Multiple improvements here:
- "Aiming to pass" is not the correct collocation for medical school admission
- "University's medical school" is redundant since medical schools are understood to be part of universities
- The phrase "aspiring medical student" is more concise and natural than "applicant who was aiming"
- "Preparing to enter" is the standard collocation for describing the process of getting into medical school

7. "and become a doctor" → [removed]
This phrase is redundant since becoming a doctor is the understood outcome of attending medical school. In professional English, we avoid unnecessary redundancy while maintaining clarity.

1. "A candidate who" → "A candidate, who"
A comma is required here because this is a non-restrictive relative clause providing additional information about the candidate. When a relative clause offers supplementary information rather than defining which candidate we're talking about, it should be set off with commas.

2. "entrance exam for a medical school" → "entrance exam for medical school"
The indefinite article "a" is unnecessary here because we're referring to medical school as a general concept or institution type. In English, when referring to educational institutions in a general sense, we typically omit the article.

3. "medical school at a university and" → "medical school and"
The phrase "at a university" is redundant since medical schools are, by definition, part of universities. In English, we aim for conciseness by eliminating unnecessary qualifiers when the meaning is already clear from context.

4. "retake the exam" → "retake it"
Using the pronoun "it" here avoids unnecessary repetition of "exam" while maintaining clarity. This follows the English principle of using pronouns to maintain cohesion while avoiding redundancy.

5. "the following year said" → "the following year, said"
A comma is needed here to properly close the non-restrictive relative clause that began with "who." This follows the rule that non-restrictive clauses must be set off with commas on both ends.

6. "responded by saying" → "responded by saying,"
A comma is required before a direct quotation in English. This is a standard punctuation rule for introducing quoted speech.

7. "to do is to become" → "to do is become"
After the phrase "what you really want to do is," we use the bare infinitive rather than the full infinitive with "to." This follows the pattern where the second "to" is dropped when "to do" is already present in the setup of the sentence.

8. "medical school no matter" → "medical school, no matter"
A comma is needed before the phrase "no matter how many years it takes" because it's an adverbial clause expressing concession. When such clauses provide additional information about the conditions or circumstances, they should be set off with commas.

1. "make up my mind" → "make up your mind"
This is a pronoun consistency error. The sentence begins with the second person pronoun "you" ("When there is something you want"), so it must maintain this perspective throughout. Switching from "you" to "my" creates an illogical shift in perspective. In English, maintaining consistent pronoun perspective within a sentence is crucial for clarity and coherence.

2,3. "so it's very meaningful" → "That's why it's very meaningful"
While "so it's" is grammatically correct, starting the new sentence with "That's why" creates a more explicit logical connection to the previous statement. This revision makes the cause-and-effect relationship more clear and emphatic, which is particularly important in explaining the significance of encouragement.