You can find all sorts of stupid things on the net! I guess you can also find equivalent misspellings in Italian? You are right. It should be 'chose'.

You are correct, "chose" is the past tense of "choose". "Choosed" is not a real word used in English.

=> choosed could be something that is chosen. Something was choosed by someone... Like "il prescelto" Example: The authors describe four cases of this syndrome and also discuss the diagnostic methods and the treatment choosed.

You are right, the past tense of "to choose" is "chose." "Choosed" is not a word. It is a mistake, or a typographical error, or possibly a joke. Here are some correct uses of various forms of "to choose:" In the winter, I look at the thermometer before I choose which jacket to wear. This morning, it was 0° C so I chose a warm winter jacket with a hood. That jacket was my choice. I could have chosen my long down coat. I don't care what brand of bread I buy, but I am very choosy about coffee--I only want my favorite brand and nothing else.