What it looks for
A passive sentence moves the receiver of an action into the subject position: “The report was written by the committee” instead of “The committee wrote the report.” In English, the passive is built from a form of be (or, informally, get) and a past participle.
The finder looks for exactly that pattern:
- a form of be (am, is, are, was, were, be, been, being) or get (get, gets, got, gotten, getting);
- then up to three words such as not, never, already, being or an adverb ending in -ly;
- then a past participle: a word ending in -ed, or one of about 220 irregular participles such as written, given, built and sent.
It skips about 110 words that usually act as adjectives after be, such as tired, interested, excited, married and based. “She was tired” is not flagged.
When a by-phrase follows, the finder shows it: “by the committee” is the actor you could move to the front.
How accurate is it?
It is a heuristic, not a grammar parser, so check each highlight. On 61 sentences we labelled by hand it found 28 of 31 passives (recall 90.3%) and raised one false alarm (precision 96.6%). The full test is on the methodology page.
It misses:
- passives with several words between the verb and the participle (“was quickly and carefully wrapped”);
- reduced passives with no be at all (“The house, built in 1900, …”);
- have passives (“She had her bag stolen”).
It can flag states that look like actions, such as “The lake was frozen solid.”
Should you remove every passive?
No. The passive is the right choice when the actor is unknown or unimportant (“The museum was founded in 1902”), when you want the receiver as the topic, or when naming the actor would be unkind. In some scientific fields it is the convention for describing methods. See when to use passive voice.
Use the finder to make each passive a choice rather than a habit. If a highlighted sentence hides who is responsible, or makes the reader wait for the point, rewrite it with the actor first.
What does the percentage mean?
It is the share of your sentences that contain at least one flagged passive. There is no correct figure: a methods section may be mostly passive, a sales email hardly at all. Use it to compare drafts of the same piece.
Is “it is believed” passive?
Yes, and it is also a hedge: it hides who believes it. The editor marks it both ways.