Andrew: Because If I speak English well,I hope to talk with many foreigner.
Correct: Because If I speak English well,I get to talk with many foreigners.
Explanation: We say "get to" instead of hope to. We say "foreigners" since we're talking about many.

Andrew: Many countries use English as conversation. So, I always try to speak and
listen to English.
Correct: Many countries use the English language as a tool in every day conversation. So, I always try to speak English.
Explanation: We can say "English language" to be more specific. Instead of  as conversation, we say "in every day conversation".

Andrew: I wish I want to go to Australia. I want to learn many culture in Australia.
Correct:I wish I could go to Australia. I want to learn the culture of the said country.
Explanation: The verb "could' is used to express possibility.To avoid redundancy or repitition of words, we say "of the said country".

Andrew: Therefore,I must talk with foreigner without a problem.
Correct: Therefore,I must learn the English language for me to be able to talk with many foreigners fluently.
Explanation: "To be able" is used to express the idea or action "in the future". Fluently means "well".

Hello, Andrew!  Wow, I commend your determination towards learning the English language. That's the spirit. I am sure that someday, you will have the chance to talk with many foreigners, particulary in Australia. Keep faith alive, Andrew!

-Teacher Isabel