These two exercises allow students to identify subjects in sentences. Both exercises uncover unconscious knowledge that native English speakers have about subjects. In the sentences in (1)-(5), the auxiliary (helping) verb moves to precede the subject from the (a) to the (b) version. In the sentences in (6)-(10), the pronoun that appears in the "tag question" always refers back to, and therefore identifies, the subject. These processes (subject-auxiliary inversion and tag question formation) are, therefore, very good tests for identifying subjects.

(1) a. The rat will sit on the wall. → b. Will the rat sit on the wall?

(2) a. The teacher can ride the bus. → b. Can the teacher ride the bus?

(3) a. It is really hot outside. → b. Is it really hot outside?

(4) a. The giant could chase Jack. → b. Could the giant chase Jack?

(5) a. Jack was chased by the giant. → b. Was Jack chased by the giant?

Describe what’s happening from the (a) versions to the (b) versions in (1)-(5)?

(6) a. The rat will sit on the wall. → b. The rat will sit on the wall, won’t she?

(7) a. The teacher can ride the bus. → b. The teacher can ride the bus, can’t he?

(8) a. It is really hot outside. → b. It is really hot outside, isn’t it?

(9) a. The giant could chase Jack. → b. The giant could chase Jack, couldn’t he?

(10) a. Jack was chased by the giant. → b. Jack was chased by the giant, wasn’t he?

Describe what’s happening from the (a) versions to the (b) versions in (6)-(10)?