13. Non-transitory computer storage having stored thereon executable code that directs a computer system to at least: detect, by application of a rule to a sentence of text, an occurrence of a sign in the sentence, the sign representing a possible occurrence of a writing problem relating to passive voice, the sign comprising a past participle followed by the word “by” and a time noun representing time, the sign not being a predetermined phrase; and determine, in connection with the occurrence of the sign, an edit to the sentence, said edit eliminating the writing problem relating to passive voice.
13. Non-transitory computer storage having stored thereon executable code that directs a computer system to at least: detect, by application of a rule to a sentence of text, an occurrence of a sign in the sentence, the sign representing a possible occurrence of a writing problem relating to passive voice, the sign comprising a past participle followed by the word “by” and a time noun representing time, the sign not being a predetermined phrase; and determine, in connection with the occurrence of the sign, an edit to the sentence, said edit eliminating the writing problem relating to passive voice. 17. The non-transitory computer storage of claim 13 , wherein the sign additionally comprises a transport noun, and the executable code directs the computer system to use a predefined plurality of transport nouns to determine whether the sign is present, each transport noun representing something that transports people or things.