Verbs must agree in tense within a sentence or paragraph. Common tense errors include switching between past and present tense within a sentence, using the wrong verb form like past perfect when simple past is correct, and using the wrong verb conjugation like "spoke" instead of "spoken". Writers should be careful to maintain consistent verb tense and form to avoid confusing or misleading the reader.

1. Inconsistent Verbs
TENSE
 Verbs must be consistent as long as the
ERRORS writer is focused on one passage or idea. Be
careful not to switch tenses within a
Tense errors occur when sentence.
the verb is inconsistent
within a sentence or a Yasir was watching television when he
paragraph, or when stands up and fixes a snack.
modifiers are unnecessarily The tense in this sentence changes from past
added and change tense. progressive to present. The appropriate
Here are the two most tense here should be past tense.
common tense errors.
Yasir was watching television when he
stood up and fixed a snack.
In this example, the entire sentence is in
past tense, with past progressive showing
the continuation action.

2. Each student will complete a reading project. He or she reads a
book, creates a visual based on the assigned book, and presents it
to the class.
In this example, the tense jump from one sentence to the next. The
assignment will take place in the future. Therefore, the work will be
completed in the future.
Each student will complete a reading project. He or she will read a
book, create a visual based on the assigned book, and present it to
the class.
The sentence is now correct. All of the actions will take place in the future.

3. Wrong Tense or Verb Form
 Some verb errors occur simply because modifiers are needlessly added.
In these cases, the tense is altered without reason. In other cases, the
wrong case is accidentally used.
I had learned to read at a young age.
In this sentence, the use of had is gratuitous. The tense is past perfect,
when it should be simple past tense.
I learned to read at a young age.
In this example, the use of past tense is appropriate. Remember that
past perfect involves more than one time period in the past.
I had learned to read before I turned 5 years old.
In this sentence, the use of past perfect is appropriate. Keep in mind
that the use of auxiliary verb changes the tense.

4. Karen has spoke Mandarin and English since childhood .
In this case, the verb to speak is conjugated incorrectly. The use of
perfect tense is the correct choice, but instead of the past tense, the
past participle is needed.
Karen has spoken Mandarin and English since childhood.
Here, the verb is conjugated correctly.
Kim drunk three glasses of strawberry juice.
This example is incorrect because the past participle of the irregular
verb to drink is substituted for the past tense.
Kim drank three glasses of strawberry juice.
This sentence correctly uses the past tense of the verb to drink.