Final answer:
The sentence is grammatically incorrect because the verb is not conjugated correctly.
Step-by-step explanation:
The sentence "Nous allons acheté un nouveau bureau." is grammatically incorrect. The correct form of the sentence should be "Nous allons acheter un nouveau bureau." The verb "acheter" (to buy) needs to be conjugated in the infinitive form. In French, the conjugation of verbs depends on the subject. In this case, since the subject is "nous" (we), the correct conjugation is "acheter".
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