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.

         Wǒ yí ɡè yuè duō méiyǒu jiē dào tā de xìn le.
False: 我一个月多没有接到他的信了。
          Wǒ yí ɡè duō yuè méiyǒu jiē dào tā de xìn le.
True: 我一个多月没有接到他的信了。

多的位置失当，概数多和数词、量词连用，表示不确定的零数。句中数字是个个位数字一，多要跟在量词个的后面。
多 here is misplaced. When used with a numeral and a measure word, the appreciate numeral 多 indicates odd number．The numeral of the present sentence is a digit 一. In this case, 多 must follow the measure word 个.