tense consistency

Use one tense for actions and states that share a time frame and a point of view. Shift to another tense when the time changes or a construction requires a particular form. Consistent tense is not uniform tense: I sent the application yesterday and expect a reply tomorrow correctly combines a past action with a present expectation.

An unexplained shift within a sequence is different: The customer approached the counter and demands a refund. In an ordinary account of the incident, use approached and demanded. The two actions happen one after the other in the same past account, so both take the past tense.

Different times. Preserve distinctions between past, present, and future reference: Jordan worked in Denver for six years, now teaches in Austin, and will retire next spring. Making the verbs uniform would erase the distinctions the sentence needs.

A sentence can also distinguish a completed event from a continuing state: The council approved the ordinance last year, and it remains in effect. The present remains is justified even within a longer account written or spoken chiefly in the past tense.

Tense and aspect. Different verb constructions can share one time frame. In Marcus was repainting the fence when the sprinklers came on, was repainting is past progressive and came is simple past. Both refer to the past. Progressive aspect presents the repainting as ongoing when the sprinklers started; consistency does not require replacing it with the simple past.

Earlier events. Use the past perfect to establish that an event preceded a past reference point: When the ferry docked, the fog had lifted. The past perfect places the lifting before the docking.

Before or after states which event came first, so a sentence with either word needs no past perfect: The mechanic replaced the battery before the rain started.

Continuing facts and reported speech. A past-tense report can include a present-tense statement that is still true: The vet told us that the clinic accepts walk-ins on Saturdays. The present accepts identifies the policy as current.

The past form accepted is also grammatical in that report. It can result from backshift, the adjustment of a subordinate verb to the past perspective established by told. Backshift does not by itself establish that the policy has changed. Retain the present when the statement’s continuing validity matters; do not change it mechanically to match the reporting verb.

Present-tense accounts. Past events can be recounted in the historical present: Last Friday the bus breaks down halfway across the bridge, and the driver tells everyone to get off. The present tense changes the manner of presentation, not the date of the incident. A sustained present-tense account is standard. A deliberate transition between past and present can also serve a rhetorical purpose, but avoid isolated shifts that have no discernible function.

Books, films, and other works. Use the literary present when discussing a work’s contents: In the documentary, the farmer loses his land but refuses to leave the valley. Use the past for completed events in the work’s creation or release: The crew filmed the valley over two winters.

Preserve time relationships within the work as well: The detective realizes that the gardener has moved the ladder. The present perfect places the moving before the realization; it does not violate the literary present. See also sequence of tenses; verb tense with since, if, and wish.