Questions & Answers about Quiero una hamburguesa.
In Spanish, the subject pronoun is often left out because the verb ending already shows who is doing the action.
- quiero = I want
- The -o ending tells you it is first person singular: I
So Quiero una hamburguesa is perfectly natural. You could say Yo quiero una hamburguesa, but that usually adds emphasis, contrast, or clarity.
- Quiero una hamburguesa. = neutral, normal
- Yo quiero una hamburguesa. = I want a hamburger