Match Wits With Our Word Wizards

(Illustrated version of Word Wizards)


In each sentence, select the best punctuation (comma or no comma) and best relative pronoun (that or which). (If the phrase is in the middle of the sentence, (,) indicates where an ending comma would go, if used.)

For example, in the first sentence, "comma" and "which" are the correct answers. The phrase "which can be back calculated . . ." is nonrestrictive, so it is introduced with "which" and is set off by commas:

For an explanation of which and that see Quirks of English.