Final answer:
The understanding of the Harappan language and culture is significantly hindered by the lack of bilingual texts, making it difficult to decipher their script and learn about many aspects of their society and daily life.
Step-by-step explanation:
The significant obstacle that hinders the understanding of the Harappan language and culture is the lack of bilingual texts. Without texts that provide a direct comparison between the Harappan script and a known language, it is extremely difficult to decipher the signs and symbols used in this ancient writing system. This absence of bilingual inscriptions is similar to what hindered the understanding of Egyptian hieroglyphs until the Rosetta Stone was discovered. The Harappan script, found on clay seals and pottery, consisted of over four hundred symbols that have not yet been deciphered. Without the ability to read and understand their language, aspects such as social structures, beliefs, laws, and the finer nuances of daily life and culture remain elusive.
Written documents are essential for understanding a culture because they provide first-hand accounts of historical events, social norms, and administrative practices. Without deciphering the Harappan script, it is impossible to know specific details about Harappan legal systems, literature, religious texts, or even the full extent of their trade practices and economic structures, despite evidence suggesting that commerce was a primary function of writing in this civilization.