English Syntax-urgent

[JDcap]

hai there..
i need help in order to solve these sentences (at below)bleary about these sentences.Please do explain it with a clear gramatical explaination, so i can give a good explaination to my students

1. the problem has come to the end.(Why we should put "has came" instead of "has come"?)
2. I currently am a post-graduate university student (if i not mistaken it should be written as "i am currently"doing my Master or Phd rather tahn the previous sentence-because " the currently" is an adverb which refers to a verb)
thanks

[Alc112]

hai there..
i need help in order to solve these sentences (at below)bleary about these sentences.Please do explain it with a clear gramatical explaination, so i can give a good explaination to my students

1. the problem has come to the end.(Why we should put "has came" instead of "has come"?)
2. I currently am a post-graduate university student (if i not mistaken it should be written as "i am currently"doing my Master or Phd rather tahn the previous sentence-because " the currently" is an adverb which refers to a verb)
thanks

Hi!!
1) because the past participle of come is come
2) You are right

cheers