1. A combined language interpreter and language learning aid device for selectively either inputting a word in a first language to obtain an equivalent word in a second language or for testing an operator's knowledge of said first and second languages, said device comprising: mode selector means for selectively setting said device in a language interpretation mode or a learning aid mode; first and second memory means for storing a plurality of words in the first and second languages, respectively, said first words being equivalent to respective second words; input means for entering a first word in the first language; access means responsive to said input means in said language interpretation mode for sequentially retrieving first words in said first language and second words equivalent to said first words from said first and second memory means; detection means operatively connected to said input means and to said first memory means for detecting equivalency between said entered first word and each retrieved first word, and for providing a signal to said access means in said language interpretation mode for advancing said access means to retrieve another first word and second word when a retrieved first word is not equivalent to said entered first word; indicating means operatively connected to said detection means and responsive to said detection means in the language interpretation mode for displaying a retrieved second word equivalent to a retrieved first word when said retrieved first word is equivalent to said input first word; random address generating means for providing random addresses in the learning aid mode; wherein said access means is operatively connected to said random address generating means and is responsive thereto in said learning aid mode for progressively randomly retrieving first words in said first language and second words equivalent to said first words; wherein said indicating means is responsive to said access means in said learning aid mode for displaying progressively retrieved second words; wherein said detection means comprises means for providing a signal for said random address generating means and said access means in said learning aid mode for advancing said access means to retrieve another first word and second word when said input first word is equivalent to a retrieved first word; wherein said indicating means is responsive to said detecting means in said learning aid mode to repeatedly display a retrieved second word when said input first word is not equivalent to a retrieved first word.