His father is even more eccentric, speaks his mind and has no manners at all.

speaks 是动词 speak 的第三人称单数形式，意思是"说话、表达"。 his 是形容词性物主代词，指代"他的"。 mind 的意思是"思想、想法、头脑"。 speak one's mind 是一个固定短语，字面意思是"说出某人的想法"，实际含义是"直言不讳、坦率地说出自己的想法"。