Final answer:
In English, it is okay to shift tenses in a sentence when the writer signals a change in time.
Step-by-step explanation:
In English, it is okay to shift tenses in a sentence when the writer signals a change in time. This is done to make the time difference clear to the reader. For example, if you are writing in the present tense but want to mention something that happened in the past, you would shift to the past tense.