Abbreviations
For example, when is it ok to use "pro" and "pra"?

More examples: num, numa

Is this accepted in formal writing or only in everyday speech?

Question

Abbreviations
For example, when is it ok to use "pro" and "pra"?

More examples: num, numa

Is this accepted in formal writing or only in everyday speech?

Answer

we use "pro" and "pra" only in everyday speech. The correct/formal is "para um" ou "para uma". 
E.g.: Nós fomos pra festa
Nós fomos para a festa

Samething for "num" and "numa". The formal way is "em um" and "em uma"
E.g. Eles estavam num carro
Eles estavam em um carro

Answer

"pro" and "pra" is only in everyday speech. 
"num" and "numa" is accepted in everyday speech and formally.

Answer

Oi, meu nome é Marcelo, Do you want to learn portuguese? I want learn english, so...add me on skype and let´s learn!!! my skype is marcelomirmar68 bye bye !

Answer

Hi Christine.
We can talk english/portuguese 50/50. My skype: brunocriado