I’ve never envied those who are learning English as a second language. With multiple words that mean the same thing or words that appear to mean the same thing but don’t, English poses a continual challenge even for the native speaker. These words are either so close in meaning or so similarly pronounced that they’re often used in place of one another when they shouldn’t be—as they mean something different.
Here are several pairs of words that are commonly mixed up:
Oral, which comes from the Latin for “mouth,” means spoken—an oral exam, for instance, or an oral presentation. Verbal has to do with words, both written and spoken. Because of this, a term such as verbal exam lacks clarity. Was the exam written or spoken? You cannot be sure. Compare this with types of nonverbal communications, such as semaphore or Morse Code, neither of which uses words.
This example illustrates how the use of verbal can be redundant:
You may respond to this notice either in writing or verbally.
What the author means is “in writing or orally”; however, by using verbally instead, the author has created an unclear statement.