If the IRS hasn't raised any issues about your 2005 tax return by now, it is safe to shred it. Last, you should keep any tax return that includes a claim for deducting worthless securities for seven years. If you've lost or discarded a tax return and later need a copy, don't worry.
Rule 2 in the âApostrophesâ section says, âUse the apostrophe to show possession. Place the apostrophe before the s to show singular possession.â. Since âworldâs biggestâ is singular possessive, you need to use âs regardless of which noun follows it.
1 To show possession (e.g., one dog's kennel, two dogs' kennel). 2  In time expressions (e.g., a day's pay, two weeks' holiday). 3  In contractions (e.g., can't, isn't, don't). 4  To show plurals (e.g., three cat's, two video's). 5  Randomly before the letter s (e.g., He like's pies.nfortunately, there are a few more quirks. Read more on apostrophes to show possession. Don't add an apostrophe to a word just because the word ends with the letter s. This is a common mistake, and it is a grammatical howler.