Why does the second group have an "a" instead of "the"?
In this sentence, the speaker is introducing a new noun (the second group of research subjects) in a general way. If the speaker had already mentioned this second group earlier, or if it had been a specific noun, "the" would be more appropriate here. Because "second group" is a non-specific noun that is being newly introduced, the article "a" is more appropriate. Ex: John spotted an apple on the group. (Non-specific, general) Ex: John didn't like the new math teacher, Mr. Smith. (Specific)
Get more Native English Expressions >