
Dabian W. answered 09/06/20
Tutor with Ph.D. - English, Writing, ESL, Test Prep, Drawing
Code-switching and clarity make grammar important. We must train ourselves to switch back and forth between formal and informal language as appropriate. It is not a matter of what is "better." It is a matter of what is most appropriate at the time. We get away with grammatical errors when settings or situations are informal, but they make us look careless and unprofessional when settings and situations are formal. For example, when competitions are close and decision-makers must make difficult decisions, they look at the "little things" or the "attention to detail" that make applicants stand out. Using formal language also reduces the chances of us being misunderstood when we speak or write.
There are numerous examples of the importance of clarity. Here is a silly but effective example of punctuation clarity as illustrated by two sentences: Let's eat, grandma. Let's eat grandma. Only the first sentence makes it clear that you are talking to grandma, not placing her on the menu. Homophones are another example of the need for clarity. The following sentences sound alike but have different meanings: The sign reads, "No reading aloud." The sign reads, "No reading allowed." The first sentence indicates that reading must be silent. The second indicates that one must not read at all.
I hope this helps.