The Korean language is natively called "Hankuko." It uses its own alphabet called “Hangeul,” which was created by King Sejong of the Joseon Dynasty in 1443. He promulgated “Hangeul” around Korea in 1446. Korea is referred to as “Hankuk” in “Hangeul” while the Korean people are referred to as “Hankuk saram.”
Writing “I love you” using “Hangeul” ideally requires the basic knowledge of writing in Korean, which does not follow the linear, horizontal format used by the English alphabet.
Know the significant differences between Korean and English, particularly with sentence structure and morphology (word structure). It’s not easy learning how to make correct translations without really studying the Korean language. In simple sentences and expressions, you can consult English to Korean dictionaries. However, to fully understand how to construct a grammatically correct sentence, it requires you to further study the language.
As a basic guide, grammatical categories in Korean don’t have any clear correspondence with those in English.
Translate the English words to “Hangeul.” While the syntax of the Korean language is quite different with English, it is important to know the major translation of the keywords given. “I” is “cho” or “na.” “Love” is “sarang.” Instead of the word “you,” what is used for the sentence is the verb “haeyo,” which comes from the root word "hada," meaning “to do.” The “nun” goes in between the “cho” or “na” because the last letter for both words end in a vowel. If the Korean word ends in a consonant, “un” is used instead of “nun.”
Construct the sentence. In this case, if the sentence “I love you” is literally translated to Korean using the given words presented in Step 2, the literal translation is “Cho nun (or Na nun) saranghaeyo.” However, the correct Korean translation is simply “Saranghaeyo.”
Korean doesn’t conjugate verbs through subject-verb agreement. In terms of grammar, Korean has a subject-object-verb word order, unlike English, which has a subject-verb-object word order. And since personal reference is avoided in Korean, it is common to encounter a Korean sentence that only consists of the verb, like in the case of “Saranghaeyo.”
Know “Hangeul” so you can write “Saranghaeyo” in Korean. Literally typing the sentence in Korean requires a Korean keyboard, but as a general rule when writing this in “Hangeul,” you write from left to right like English. However, there are times that you write parts of a syllable below particular letters belonging to the same syllable.
For “Saranghaeyo,” use the Korean counterpart of letter “S” and add one of the Korean vowels equivalent to letter “A.” This is your first syllable written horizontally together like typical English letters. Then you use the counterpart of letter “R” and add the vowel “A” again. This is the first part of your second syllable. Continue this part by adding the Korean equivalent of “NG” and place it under the “R-A.” The third syllable involves the Korean counterpart of the letters of “H-AE” to be written in a horizontal way like “S-A.” Then write the “YO” in a linear fashion after the “H-AE” using the “YO" letter in Korean.
Note that "S-A" are two different letters in Korean combined together to create one syllable; the same thing with "R-A" and "H-AE." The "NG" is a letter that works as a part of a syllable. "YO" is a letter that can work as a separate letter considered as an independent syllable or a part of a specific syllable.