Paulenrique is correct. When stating a profession, the article a/an is never used. Você é professor (You are a teacher), Você é engenheiro (You are an engineer)
The e in arquiteto is an accented e. It is an open e, pronounced 'eh' with the mouth open. T and d do not change when followed by an open e. Portuguese also has a closed 'e', pronounced somewhat like 'ay' (actually more like 'eh' but with the mouth half closed). It also has an unaccented 'e' pronounced more like the i in 'it'. T goes to ch and d goes to j when followed by an unaccented e
duo states that "Você é arquiteto" translates to "You are an architect" properly. Would it be wrong to say "Você é um arquiteto"?
no, that's not correct, but normally used when you have more context (você é um arquiteto bem requisitado).
I've noticed in many of the occupation lessons that e' or is is used instead of sao or are. Is this something unique to occupations? If I say "Voce e' arquiteto" instead of "Voce sao arquiteto," am I saying it with proper Braz. Portuguese grammar, please?
Kind of. The sentence must have the question mark at the end and also must be pronounced with a questioning tone of voice
So in this form of sentence when translating, even when an article is not present - should we always assume an indefinite article rather than a definite? I used "the" and got it wrong.
In Portuguese, when talking about occupations and job positions, they themselves become an adjective to the person with the verb ser. You can use the indefinite article but it's far less common.
The definite article, in this and many other contexts, we use to specify a person. Basically the same usage as in English.
Você é enfermeira? — Are you a nurse? [COMMON]
Você é uma enfermeira? — Are you a nurse? *(the same meaning in this context) [LESS COMMON]
Você é a enfermeira? — Are you the nurse? (specifying the nurse, it has a different meaning — you may guess what it is)