If someone who does not speak Hebrew hears the Meghilla read in Hebrew, from a Kosher scroll written in Hebrew, he fulfills his obligation even if he does not understand what is being said.
It says in the Shulhan 'Aruch that if a Meghillah is written in a non-Jewish language, only someone who is familiar with that language can fulfill his obligation by reading it. There are certain restrictions connected with this, however.
The universal custom that we follow nowadays, that we should not deviate from, is that the Meghilla must be written in the Holy Tongue (Hebrew) in accordance with the rules for writing a Meghillah, and must be read only in the Holy Tongue. This applies to everyone, men and women, even if they are not familiar with the Holy Tongue, as we mentioned above.
(See Shulhan 'Arukh 690: 8, 9. Kaf Hahayim, ibid, Oth 56, Q. Sh. ‘A. H’ Toledano, ibid, 17)
