Gender confusions

Question

Hi, if I want to say he is one of the nicest people I know - es uno de las personas más agradables yo sé, is this correct? I am asking this because I'm confused whether you can use uno and a feminine noun like personas and vice versa in the same sentence because all of the examples do not have this sort of example.

Accepted Answer

Hola Hola123
Your sentence: 
"es uno de las personas más agradables yo sé."
would be:
"Es una de las personas más agradables que yo conozco."
We have a similar sentence at the end of the lesson saying:

Mi vecina Lola es una de las personas menos organizadas que conozco.
My neighbour Lola is one of the least organised people that I know.

As you can see you need "una" (not uno) to agree with the feminine noun "personas", even though the subject is masculine. "He is..." Then you always need the relative "que" in Spanish, you can't drop it like in English. Also, when we talk about "knowing people" we use the verb "conocer", not "saber". I hope this clarified it.
Saludos
Inma

Answer

Hmmm . . . RAE needs to make persona m/f like alteta, asistante y ayudante. You can use uno or una with them as desired/required.