What's wrong with this sign? Is it a grammatical or a mechanical problem? Both!
What are mechanics? Mechanics refers to the rules of the written language, such as capitalization, punctuation and spelling (Lethbridge College).
What's missing from this sign that makes it hard to understand?
Without the necessary period, the noun hunting (gerund) is easily mistaken for a verb (present participle), and the noun pedestrians becomes the direct object of hunting! Outdoor sports just became a lot more dangerous.
The second sign shows another example of how mechanics govern the brain's grammatical expectations. The way the sign reads, even though the fields are closed, no one will be punished for entering the field.
How is it that sign says the opposite of what it means? Missing its exclamation point, the noun trepassing (gerund) is mistaken for an adjective, describing violators.
Why does the brain do this? For an English-speaker, when one noun immediately follows another, the brain's tendency is to force the first noun into a role of descriptor, an adjective. So, the nouns farm and house, when one follows the other, develop a new relationship (adjective + noun): farm house.
Some uses of this relationship have become so regular that new, compound words have been formed:
street + light = streetlight
rail + road = railroad
home + work = homework (!)
Possessive Pronouns in the Compound Context
Now that you’ve got the basics of possessive pronouns down, what if you want to express joint ownership? Well, you certainly don’t say “mine and hers” or “her and I’s.” I’m not sure that this particular blaspheme has ever been committed to writing. I don’t even know how “I’s” should be spelled. (It probably shouldn’t have an apostrophe, but there’s no sense polishing the floorboards on a sinking ship). Though this particular mistake may not be common in writing, it pops up frequently in speech. Have you heard someone say something like this recently (or, gasp, said it yourself)?
Jim and I’s meeting is after lunch.
Or, Me and Mary’s depositions went well.
When two people co-own something, you can express that co-possession in one of two ways — with an apostrophe and a noun or with a pronoun. Use one or the other, but not both.
When joint ownership is expressed with possessive pronouns rather than two nouns, do not use an apostrophe with the pronoun. The sentence “Jim and my’s meeting is after lunch” hurts your ears, right? So instead, add the apostrophe to Jim but leave the pronoun alone. “Jim’s and my meeting is after lunch” is correct. The easiest fix, of course, might be to rephrase your sentence and just use our instead, as long as it’s clear from the context who our includes.
The same rule applies to all the possessive pronouns, not just my. At the risk of overburdening Jim, here’s how they would look:
Jim’s and your client will arrive at 3:00.
Jim’s and her brief is due next week.
Jim’s and our trial begins in May.
Jim’s and their vacation will have to be postponed.
Poor Jim.
Frost, Elizabeth. “The Legal Writer: Primary on Pronouns.” Welcome to the Oregon State Bar Online, Oregon State Bar, May 2012, www.osbar.org.