Hola Thomas. "He wears socks" is like "El usa calcetines" o "El lleva puestos calcetines". If you say only "(El) lleva calcetines", people don't know exactly if he is wearing or only he is carrying it. It's ambiguous. I could tell you that you would use "Agrego fresas" or "Agrego unas fresas" or "Agrego algunas fresas" in most cases. But, depends on how specific you want to be or how much information you want to give to the other person or people. With "Agrego fresas" you don't give much information about how many strawberries. With "Agrego unas fresas" or "Agrego algunas fresas" means that you are adding a few strawberries. If you want to be more specific or exactly you need to say "Agrego 5 fresas", but as I told you", in most cases it's not necessary because it's not relevant at that moment. Regards.

Hi Thomas, how are you? It's an interesting question, "Unos" is an indefinite article "artículo indefinido", in this case, it is plural so it works like the word "algunos"(some), so when you use it, you are talking about a little part of the group, if you say "Agrego fresas", you're talking about all or almost all of "fresas", but if say "Agrego unas fresas", you are talking about a few "fresas" not many. It always works in the same way. if you say: "tengo autos", the people will think :"él tiene muchos autos" but if you say: "tengo unos autos", the people will think: "él tiene 2 o 3 autos" If you say: "llevo calcetines", the people will think: "aparte de los que usa, quizás tiene algunos de reserva en el bolsillo" but if you say: "llevo unos calcetines", the people will think: "Claro los que llevas puestos" have a nice day.