Questions & Answers about Eu recebi a carta ontem.
The verb is receber. Why does it end in -i here?
Because it is in the simple past tense (pretérito perfeito) for the eu (I) form! To form the past tense for regular -er verbs, you drop the -er and add -i. So, receber becomes recebi (I received). Good news: regular -ir verbs also use this exact same -i ending for eu in the past tense.
Could I just say Recebi a carta ontem and leave out the word Eu?
Does carta mean "card"?
It looks like it, but it is a false friend! Carta translates to "letter" (as in mail) or "playing card". If you want to talk about a credit card, a birthday card, or a business card, you need to use the word cartão.
Does the word ontem have to go at the end of the sentence?