The word ‘contento’ translates as content, happy, satisfied, or pleased. The exact word for ‘happy’ is ‘felice’ and happiness is ‘felicita’. However, the phrase ‘sono contento’ is used far more often than ‘sono felice’ in order to express happiness. It’s a nice of saying you are ‘content’, or that effectively you have ‘had your fill’ and need no more at present.
Here is how we would express the different stages or levels of happiness (or contentment) in Italian:
Sono contentissimo (or sono stracontento) – I’m extremely happy. This is about as happy as one can get!
Sono molto contento (or sono assai contento or sono contento assai) – I’m very happy. Note that “molto contento” is not exactly the same as “contentissimo”, even though most Italian/English reference books will translate the “issimo” as “very”. Using “issimo” tends to convey much more than “molto” alone.
Sono abbastanza contento – I’m quite happy. Not too much and not too little, just enough.
Sono contento – I’m happy. The most basic form. Note that it is not the same as the ‘abbastanza’ form. The use of ‘abbastanza’ implies that you are happy enough, or that you have your fill of happiness for the time being, although in principle you could have more! Without ‘abbastanza’, you are saying that you are just happy, but not disclosing whether you are happy enough…
Sono poco contento – I’m not as happy as I could be. This implies that something is wrong, but you are not entirely unhappy.
Non sono contento – I’m not happy. Now we’ve crossed over completely into the negative.
Non sono per niente contento (or non sono contento per niente or non sono affatto contento) – I’m not happy at all.
Note that the opposite of ‘contento’ is ‘scontento’ (meaning unhappy, displeased, or discontent), and in fact you could use all of the above forms substituting ‘scontento’ in place of ‘contento’, depending on whether you want to emphasise happiness or unhappiness. Although, for example, the phrase “Sono molto scontento” is the logical inverse of “Sono poco contento”, they communicate different sentiments. The former means that you are very unhappy and the latter that you aren’t too happy. Note quite the same, just as in English.