When a speaker who knows a language well makes a grammatical ...

[aabwk4]

When a speaker who knows a language well makes a grammatical error in conversation, this is
 
  a. probably a performance error, unrelated to linguistic competence.
  b. evidence that the language is highly complex and constantly changing.
  c. proof that all speakers of a language are not equally well-versed in its rules.
  d. evidence that the speaker's personal linguistic style is still evolving.

Question 2

Recent research shows that African elephants can communicate with one another at a distance in which way?
 
  a. supersonically, through extremely high pitched sounds that are similar to dog whistles
  b. by flapping their large ears in particular patterns
  c. subsonically, through deep rumbles that are carried through the ground
  d. by marking messages on trees with their tusks

[makaylafy]

Answer to Question 1

a

Answer to Question 2

c