Questions & Answers about Ontem eu cortei um pêssego e uma ameixa para colocar no iogurte.
Ontem means yesterday, and putting it at the beginning is a very common way to set the time frame right away.
Portuguese word order is fairly flexible here, so these are all possible:
- Ontem eu cortei um pêssego e uma ameixa...
- Eu cortei um pêssego e uma ameixa ontem...
Starting with Ontem just gives a natural time-first emphasis.
That is true: Brazilian Portuguese often omits subject pronouns when the verb already makes the subject clear.
So you could also say:
- Ontem cortei um pêssego e uma ameixa para colocar no iogurte.
Including eu is still completely natural. It can make the sentence a little clearer, a little more conversational, or slightly more emphatic. In Brazilian Portuguese, speakers use subject pronouns more often than in European Portuguese, so eu here sounds normal.