No, they are not the same in English. I apologize means i am sorry for something I caused. I'm sorry often is said with no personal responsibility. As I'm so sorry your husband died. You would not apoligise for the death of a loved one, unless you were somehow involved in the death.
No it shouldn't in the word bank it didn't show a contraction so therefore it shouldn't be accepted anyways if you have a Windows supported app it should automatically know what the system wants and change it so. :)
what i put down: sorry, i don't speak portugese as it turned out, i misspelled Portuguese :)
Bonzer, the 'u' is inserted to keep the 'g' hard. (This sentence was brought to you by your local pharmacy.)
In the Western Romance languages, the 'g' in the letter combinations 'ge' and 'gi' sounds different from the 'g' in all other combinations. You can find the same in English: the 'g' in "gesture" and "gist" sound different from those in "gargle", "gorge", "gust" or "grammar".
So without the 'u', "Portuguese" would sound like "portujees". Just like "guest" would become "jest".
Well. "I'm sorry I don't speak Portuguese.", is not the same as "I'm sorry, I don't speak Portuguese." In the first, the speaker regrets not speaking the language, while in the second the speaker regrets being unable to do whatever he was asked to do earlier in the conversation, and only mentions the language as an explanation. Not that I expect Duolingo to be able to treat such a difference correctly, but it's still worth mentioning.
Bonzer, it would normally count as a typo, but Duolingo checks the mistyped words against all words it has in its database to see if there is a word in the English language that matches your mistype. If it finds one, it'll be graded as wrong.
Apparently somewhere in the millions of sentences, a "Portugese" slipped through as an accepted translation. So now whenever you misspell it, Duo will find that one translation and think it's also a valid word which you used in error, so it won't accept your sentence.