Final answer:
The tense used for permanent or usual situations is the simple present tense.
Step-by-step explanation:
The tense used to describe a permanent or usual situation in English is the simple present tense. This tense is used to express actions or conditions that are generally true or that occur regularly over a period of time. For example, "She works at the library" describes a usual routine and would be written in the simple present tense. It is important to maintain verb tense consistency in your writing to avoid confusion and to present information clearly.