Learn Hardcore Korean: jeoneun jeonjareinjiro keopireul dewoyo.

저 is the humble/polite form of “I” in Korean and is used in most everyday conversations to show respect. 나 is an informal version of “I” and can sound rude or too casual if you use it with people who are not very close to you. Adding -는 makes 저는 the topic of the sentence (“as for me”).

What does the particle -는 do in 저는?

-는 is the topic marker. It highlights “저” as the thing we’re talking about (“as for me”) and sets the stage for the rest of the sentence. It can also imply contrast (“as for me, … but someone else…”) or underline known information.

Why is it 전자레인지로 and not 전자레인지에서 or 로보닥터?

-로 marks the instrument or means by which an action is performed (“with” or “by means of”). Here, it tells you that you heat the coffee by using the microwave. In contrast, -에서 would mark a location (“at” or “in”), so 전자레인지에서 would emphasize “inside the microwave” rather than “using” it. (And 로보닥터 isn’t a real word—just a playful mix of 로 and a random English word!)

Why is 커피를 placed before the verb 데워요?

Korean follows Subject–Object–Verb (SOV) word order. The typical sequence is:

Subject (저는)
Instrument/Adjunct (전자레인지로)
Object (커피를)
Verb (데워요)

English uses SVO, so it can feel backwards at first.

Why is the verb 데워요 and not 데웁니다 or 데우어요?

데워요 is the polite present tense form (해요 style). You take the stem 데우- and add -어요, then contract 우 + 어 → 워.
데웁니다 is the formal present tense form (합니다 style). It’s more formal than 데워요.
데우어요 is uncontracted and doesn’t actually occur in speech or writing; it always contracts to 데워요.

Is 데우다 the same as 끓이다?

No.

데우다 means “to warm up” or “to heat” something that’s already cooked or prepared (like coffee or leftovers).
끓이다 means “to boil” (e.g., water, stew, noodles) until bubbles form.

You’d 데워요 coffee but you’d 끓여요 water.

Could I say 커피를 전자레인지에 데워요 instead of 전자레인지로?

You could grammatically, but it would sound odd. 전자레인지에 stresses location (“inside the microwave”), while 전자레인지로 is the natural way to express “using” the microwave as the tool or means.

Why is 전자레인지 a loanword and not a native Korean term?

전자레인지 comes from English electric + range, borrowed through Japanese 電子レンジ (denshi renji). Modern appliances in Korean often take English-derived names because they entered the language relatively recently, and the loanwords became standardized.