We have talked about the simple present tense, the present continuous tense, the present perfect tense, and the present perfect continuous tense. Let’s review the four tenses briefly by comparing these four sentences. Each sentence uses the same verb.
Maria reads a novel in her spare time –> the simple present tense; it is Maria’s habit to read a novel.
Maria is reading a novel right now –> the present continuous tense; the focus is on the action in progress at the moment of speaking.
Maria has read two novels so far –> the present perfect tense; the reading started and completed at an unspecified time in the past; the focus is on how many novels he has read until now.
Maria has been reading a novel for two hours –> the present perfect continuous tense; the reading started two hours ago and is still happening at the moment of speaking; the focus is on how long the reading has happened until now.