「 一人の人しか言わないことを一般化するのは、よくありませんよ」 English translation: "It isn't good to generalize something that only one person says." We can divide the statement into 3 parts, ①一人の人しか言わないことを (something that only one person says) ②一般化するのは、 (to generalize) ③よくありませんよ (isn't good) The way that the 3 parts are connected are also important: ① and ② have the particle 「を」 in between them, therefore the verb "to generalize" is being done to part ① ② and ③ have 2 particles connected to each other 「の」 and 「は」 「のは」 holds a similar meaning to 「ことは」, which means something like "the matter is" by itself, but when put in this context, it indicates an action "To (do an action) is...". So ② and ③ connected will become "the action of generalizing is not good" or "to generalize is not good". When we put them all together, it becomes "To generalize something that only one person says is not good" Or more naturally speaking, "It isn't good to generalize something that only one person says." I hope this helped :)