Я говорю́ по-ру́сски
Я говорю́ по-ру́сски. = I speak Russian Would be also correct to say Я говорю́ ру́сски without the по- in front of the word ру́сски? Or do you need the по- in по-ру́сски?
you need the по- in front of the word ру́сски . Because in russian when you want to say ''I speak russian (or english, or portuguese, etc)" you say something like "i speak in the russian way". So if you want to say that "something done in a certain way". you need to use по- in front of the word.
you need the first 'Я говорю́ по-ру́сски.'
Why? Because it is an idiom in (correct) Russian. So do not leave 'по' out if you want to be (fully) correct.
This по- is used as prefix for all languages: по-английски, по-венгерски, ...