Foreigners often make some strange mistakes in Chinese when they study the most difficult language--- ---Chinese. We try to analyze typical sentences to correct these errors.

          Zhèlǐ yǒu duō rén.
False: 这里有多人。
           Zhèlǐ yǒu hěnduō rén.
True: 这里有很多人。

句中的“多”不能单独作定语，“多”的前边应当加“很”。一并作中心语“人”的定语。“很”表示程度的意义不明显。
多can not act as an attributive in isolation. It must be used in combination with 很 before it to serve as an attributive of the head word（人）. Here 很 does not hold a definite implication of a high degree.