Questions & Answers about Ich nehme das Buch vom Tisch.
Because the subject is ich. The verb nehmen is conjugated like this in the present tense:
- ich nehme
- du nimmst
- er/sie/es nimmt
- wir nehmen
- ihr nehmt
- sie/Sie nehmen
So with ich, the correct form is nehme.
A useful detail: nehmen is a stem-changing verb, but the vowel change to i only happens in du and er/sie/es forms, not with ich.
Das Buch is the direct object of the sentence — it is the thing being taken.
In German, the direct object usually goes in the accusative case. The noun Buch is neuter, and the article das is the same in both nominative and accusative:
- nominative: das Buch
- accusative: das Buch
So the case changes grammatically, but here you do not see a different article form.