Grammatical misagreement in tense

I – Present, present perfect

Introduction

Each of the sections of a journal article contains anticipated conceptual components, which can be expressed by a specific verb tense for the perspective of time and the degree of certainty. In this regular feature, distractions of the present and present perfect tense are exemplified, revised, and analysed. The examples are organised first according to anticipated conceptual component, second to tense (present, present perfect), and third to time or certainty in the context of the anticipated conceptual component.

As stated in books on linguistics, there are only two tenses: present and past. All the others are considered as aspect requiring the auxiliary will (future), have (present perfect), had (past perfect), to be (progressive). However, for simplicity, the more common expression tense is used.