Explain the difference in meaning and grammatical function between the aorist tense ('gelir') and the present continuous tense ('geliyor') when used with the verb 'gelmek' (to come).

The aorist tense, exemplified by 'gelir' from the verb 'gelmek' (to come), primarily denotes actions that are habitual, regular, general truths, or potential. Its grammatical function is to express an action without a specific beginning or end within a defined time frame; it signifies an action that occurs broadly or repeatedly. The form 'gelir' is constructed by adding the aorist suffix '-ir' (which varies as -r, -ar, -er, -ır, -ir, -ur, -ür depending on the verb stem and vowel harmony) to the verb stem 'gel-'. For example, 'Her gün okula gelir' means 'He/She comes to school every day,' indicating a regular, habitual action. It can also express potential or possibility, such as in 'Belki yarın gelir,' meaning 'Perhaps he/she will come tomorrow,' suggesting a potential future event. The aorist emphasizes the action's general occurrence or its likelihood, not its ongoing nature at a specific moment. It implies a wider, often indefinite, temporal scope.

In contrast, the present continuous tense, exemplified by 'geliyor' from 'gelmek,' primarily describes an action that is currently in progress at the moment of speaking or happening around the present time. Its grammatical function is to focus on the ongoing nature or temporary state of an action. The form 'geliyor' is created by attaching the present continuous suffix '-(i)yor' to the verb stem 'gel-,' with the 'i' serving as a buffer vowel to facilitate pronunciation and conform to vowel harmony rules. For example, 'Şimdi geliyor' means 'He/She is coming now,' clearly indicating an action actively unfolding at the precise moment of speech. It can also refer to actions occurring in a current, temporary period, such as 'Bu aralar Ankara'ya geliyor,' meaning 'He/She is coming to Ankara these days,' indicating a temporary, ongoing activity. Furthermore, the present continuous is commonly used to express definite future plans or arrangements when combined with a time expression, as in 'Yarın bize geliyor,' meaning 'He/She is coming to us tomorrow.'

The fundamental difference in meaning and grammatical function between 'gelir' and 'geliyor' lies in their aspect and temporal focus. 'Gelir' (aorist) focuses on the *regularity*, *habit*, *generality*, or *potential* of an action, spanning an indefinite or broader time frame, and does not specify if the action is happening *now*. 'Geliyor' (present continuous) focuses on the *ongoing nature* or *progress* of an action at a specific, often immediate, moment in time, or within a current temporary period, or as a definite future arrangement. The aorist describes *what generally happens or can happen*, while the present continuous describes *what is happening now or is definitely planned*.