Dvi is a numeral (meaning "two") and, as a result, it doesn't follow the typical declension patterns of nouns. It acts more like an adjective and takes on the form of the noun it modifies.
Here's a simple breakdown of how it would typically be used in a sentence:
* Nominative: द्वौ (dvaũ) - Used for the subject of a sentence. Example: द्वौ पुस्तकौ स्तः (dvaũ pustakau staḥ) - "There are two books."
* Accusative: द्वौ (dvaũ) - Used for the direct object of a sentence. Example: अहं द्वौ पुस्तकौ पठामि (aham dvaũ pustakau paṭhāmi) - "I read two books."
* Instrumental: द्वाभ्याम् (dvābhyām) - Used to indicate the means or instrument. Example: द्वाभ्याम् पुस्तकाभ्याम् अहं पठामि (dvābhyām pustakābhyām aham paṭhāmi) - "I read with two books."
* Dative: द्वाभ्याम् (dvābhyām) - Used to indicate the recipient or beneficiary. Example: द्वाभ्याम् पुस्तकाभ्याम् दत्तम् (dvābhyām pustakābhyām dattam) - "It was given to two books."
* Ablative: द्वाभ्याम् (dvābhyām) - Used to indicate separation or origin. Example: द्वाभ्याम् पुस्तकाभ्याम् आगतः (dvābhyām pustakābhyām āgataḥ) - "He came from two books."
* Genitive: द्वयोः (dvayoḥ) - Used to indicate possession or relationship. Example: द्वयोः पुस्तकानाम् (dvayoḥ pustakānām) - "Of two books."
* Locative: द्वयोः (dvayoḥ) - Used to indicate location. Example: द्वयोः पुस्तकानाम् उपरि (dvayoḥ pustakānām upari) - "On two books."
Important Note:
* The forms of "dvi" change based on the gender of the noun it modifies. In the examples above, I've used masculine nouns, so the forms are accordingly.
* The exact forms of "dvi" may vary slightly depending on the noun's grammatical case and gender.
* It's generally easier to learn the declension of nouns and then understand how "dvi" integrates with those patterns.
Let me know if you have more questions or would like a more detailed explanation of any particular case!