Step 1: Understanding the Concept:
The task is to identify errors in subject-verb agreement, countable/uncountable noun usage, and prepositional usage.
Step 2: Key Formula or Approach:
Approach: Analyze each sentence individually against standard formal English grammar rules.
Step 3: Detailed Explanation:
A. Incorrect: "Cars" is countable; it should be "fewer cars," not "less."
B. Correct: Standard comparative usage.
C. Incorrect: Should be "since Monday" to indicate a starting point in time.
D. Correct: "Know how to" + verb is the correct idiomatic structure.
E. Incorrect: For people, the relative pronoun "who" is preferred over "that" in formal contexts.
F. Correct: "Media" is plural (of medium); when they are divided (acting as individuals), a plural verb "are" is correct.
Step 4: Final Answer:
The correct sentences are B, D, and F.