Tenses exercises in Nepali grammar are designed to enhance learning and foster fluency in the language. The challenge they offer is multi-faceted, addressing various elements such as verb conjugation, word order, vocabulary and context awareness.

Firstly, in Nepali grammar, the verb typically comes at the end of the sentence, and this rule should be well-attended in tenses exercises. Conjugating verbs properly, according to time and tense, remains vital for creating sensible sentences. For instance, Nepali has different forms for the past, present, and future tenses. Learning and practicing these rules help to improve fluency.

Tenses exercises also involve learning auxiliary verbs, which aid in forming perfect, continuous, and perfect continuous tenses. Auxiliary verbs like ‘गरेको’ (has done), ‘गरिरहेको’ (is doing) and ‘गर्नेगरी’ (will be doing) are crucial for building sentences in different tenses. These auxiliary verbs, when combined with the main verb, depict a clearer picture of the event’s timeframe.

Vocabulary variation is another interesting feature of tenses exercises, enabling learners to use suitable words for particular settings. For example, the present tense is commonly used in daily conversations, future tense in planning and making promises, and past tense in telling stories or describing previous events.

In conclusion, tenses exercises in Nepali grammar are a great way to improve conversational and written skills in the language, cultivating precision and a better understanding of the language structure.