It depends on the nature of the "non-believer".
A non-Jewish person is called a Gentile or Goy (גוֹי), but gentiles are NEVER referred to as "non-believers". Unlike other religions, Jews do not assess the beliefs of non-Jews, (or regard them as believing less than what Jews believe).
If the non-believer is a Jewish heretic, the person is usually called a Kofer or Apikorus, but these terms are only used among Orthodox Jews. Non-Orthodox Jews shy away from the concept of heresy, and would generally use the terms of their native language, such as "cultural Jew," "Humanistic Jew," "Secular Jew," "atheist," or "agnostic". The Hebrew equivalents of these phrases are:
humanistic Jew: "yehudi hoomanisti" (יהודי הומניסטי)
cultural Jew: "yehudi tarbutí" (יהודי תרבותי)
secular Jew: "chiloní" (חילוני)
atheist: "ah-teh-eest" (אתאיסט)
agnostic: "kofér" (כופר)
There is no special name for someone who studies Hebrew.
A mathematician. Or in friendly, informal terms: a math whiz.
"Call" has a few meanings which have different words in Hebrew. Mainly: 1. Calling someone by their name, or summoning them, is "Likro". 2. Calling someone on the phone is "Lehit'ka'sher".
Christians still call the Hebrew Bible the Old Testament.
"Gym Rat" "Workout Freak" those are just some slang terms
To call someone "babe" in Spanish, you can use the term "cariño" or "bebé." These terms are commonly used as affectionate nicknames for a loved one or significant other in Spanish-speaking cultures.
A kohen.
Most often the terms used would be Squire or Goodman or Young Master
There is no Hebrew name for Frank. You would just call him Frank. You can spell it פראנק
What do you call group terms such as swarm and ream?
Like terms.
In Hebrew, you would say, "call a child by his name":קָרָא לַיֶּלֶד בִּשְׁמוֹ (kara le-yeled bishmo)