Be careful with ingenious and ingenuous.
Sometimes a single letter can make a great deal of difference to the meaning of a word. Take, for example, the two words ingenious and ingenuous. Ingenious means clever, original or inventive. It derives ultimately from the Latin word ingenium, which means a natural capacity or talent. It’s the same word from which engine, among other words, derives.
So, a talented or clever person could be described as ingenious, as could a device or idea that is particularly clever or well-suited to its purpose.
Ingenuous, however, means innocent and unsuspecting, perhaps in a childlike way. It derives from a separate Latin word, ingenuus, meaning native or freeborn. It’s the same word from which ingenue/ingenu derives, meaning a naïve young woman/man. Originally, ingenuous tended to have a more positive sense than it does now : it meant candid, frank or honourable. Today, the word often has more negative overtones. To be ingenuous is to be unsophisticated.
So, the one letter difference between ingenious and ingenuous gives us two words that actually have more-or-less opposite meanings. Be careful which you use.