Some past participles are irregular. For example ... you have learnt the perfect tense. Has aprendido el pretérito perfecto. The first part of the perfect tense is the present tense of the ...

The clauses above bear examples of a common verb tense: the present perfect continuous. This is the tense that indicates an action that started in the past and continues now. While the present ...

One’s tense will vary depending on what one is trying to convey within their paper or section of their paper. For example, the tense may change between the methods section and the discussion section.