Yo recibí una a por mi trabajo. Eso me enseñó que yo era capaz de conseguir una buena nota en un proyecto difícil
1. does the "a" belong before por?
2. is it a period after trabajo?
una A por mi trabajo = capitalize A so it's clear that it is a grade.
1. capital A, yes
2. period after trabajo. = yes
Sra
1. Based on the context of the sentence, it seems like you might have made a typo. Instead of "Yo recibí una a por mi trabajo," it should be "Yo recibí una 'A' por mi trabajo." In this case, the word "A" is referring to a good grade or mark that you received for your work.
2. Yes, there should be a period after the word "trabajo" to indicate the end of the sentence. So the corrected sentence would be: "Yo recibí una 'A' por mi trabajo."