Quick! Check your calendar—what were you doing last March 4th? If you weren't celebrating National Grammar Day, you missed a fine celebration. No worries, though. You'll get another chance March 4, 2016. But that leaves you fewer than eight months to prepare.

Errors in grammar, syntax, and punctuation rumple your smooth use of Standard American English (SAE), the variety of English generally expected in presentations and documents. Any such rumple may erode your credibility, the audience's take on how believable and trustworthy you are. It may diminish the clarity and thus the persuasive power of your message. And if rumple after rumple tugs at the fabric of your grammar, listeners or readers may become so focused on the number of errors that they withdraw their attention.

To get you started on the next March 4th holiday celebration, then, we present five grammar errors that decrease communication effectiveness and so are best remedied.

1. Fewer/Less

Use "fewer" for things that can be counted (things that are plural): months, reports, capsules

  • He is responsible for fewer reports this quarter.

Use "less" for things that cannot be counted (things that are singular): time, anxiety, fanfare

  • Most of them now have less anxiety about delivering presentations.

2. I/Me/Myself

Use "I" as the subject of a sentence or clause

  • James and I finished the draft.
  • James will check the reference list while you and I proofread.

Use "me" as the object of a sentence or a preposition (just as you would "her," "him," "them")

  • That regulation gives me three months to file an appeal.
  • Between you and me, I thought we'd be finished with this by now.
  • Geraldo assigned the second account to Van and me.

Use "myself" only as an intensifier or to refer back to the subject

  • I myself would have tried several other methods.
  • I told myself to leave time after that meeting.

3. Their/There/They're

"Their" indicates possession (just like "his," "her," "my," and "your" do)

  • At least their delivery won't be delayed.
  • As impressive as their summary seemed, it omitted several key points.

Use "there" to refer to a place (just as you would use "here")

  • Flying there costs less than taking the train.
  • I found it there.

Use the contraction "they're" to mean "they are" (similar to "we're" for "we are" or "you're" for "you are")

  • They're on the way now and should arrive by noon.
  • I'm not quite sure which listing they're discussing.

4. Comprise/Consist

Use "comprise" to mean made up of (never uses "of")

  • The United States of America comprises fifty states, a few of which are quite small.
  • The leading team comprises players from Korea, Canada, and Puerto Rico.

Use "consist" to mean made up of (requires "of")

  • The United States of America consists of fifty states, some of which are quite small.
  • The leading team consists of players from Korea, Canada, and Puerto Rico.

5. Apostrophes

Use an apostrophe to create a contraction; it replaces the omitted letter(s)

  • It's scheduled for Wednesday. ("it's" = "it is")
  • This case resembles the one we're currently investigating. ("we're" = "we are")

Use an apostrophe to show possession (but not with the pronouns "its," "theirs," "yours," "hers," "his")

  • My sister's spouse heads that committee.
  • Marisa distributed presenters' schedules yesterday.

There you are. Five kinds of mistakes that writers and presenters of all levels and professions are liable to make. Start working on them today, perhaps, to celebrate Second Half of the Year Day. Happy holiday!