Learn Hardcore Korean: jeoneun maeju sijangeseo gwaireul sayo.

-는 is the topic marker, showing that 저 is what the sentence is about and framing a habitual statement. -가 is the subject marker, which puts more emphasis on the doer of the action. When you’re describing general routines, Koreans usually use 저는 rather than 제가.

What does 매주 mean and where should it go in the sentence?

매주 means every week and functions as a frequency adverb. Korean typically orders elements as time → place → object → verb, so starting with 매주 highlights the weekly habit:
매주 시장에서 과일을 사요.
You could also place it just before the verb, but leading with it is most natural.

Why do we use 시장에서 instead of 시장에 here?

The particle -에서 marks the location where an action takes place, so since you’re buying fruit at the market, you use 시장에서. -에 would mark a static location or the target of movement, not the site of an action like buying.

Why does 과일 take -을 (과일을)?

Direct objects in Korean take -을 if the noun ends in a consonant (and -를 if it ends in a vowel). 과일 ends with ㄹ, so you attach -을 to indicate that fruit is what you’re buying. Particles clarify each noun’s role even when context makes it clear.

What is the difference between 사다 and 사요?

사다 is the dictionary form meaning to buy. To speak politely in the present tense, you drop -다 and add -아요 (because the stem vowel is ㅏ), then contract 사아요 into 사요. Thus 사요 is simply the everyday polite present-tense form of 사다.

Can I use a more formal ending like 삽니다 instead of 사요?

Yes. 삽니다 is the present-tense formal polite ending (합니다체). It’s common in news, presentations, or very formal contexts. Saying
저는 매주 시장에서 과일을 삽니다
just shifts the sentence into a more formal register.

Is it okay to drop 저는 and start with 매주?

Absolutely. Korean often omits subjects when they’re clear from context. You can simply say
매주 시장에서 과일을 사요
and listeners will understand that you’re talking about yourself.

Is the order always time → place → object → verb in Korean?

That is the most common word order, but it isn’t rigid. You can move elements for emphasis—for example,
시장에서는 매주 과일을 사요
stresses the place. However, beginners usually stick to the default time → place → object → verb pattern.

What’s the difference between 시장에서 과일을 사요 and 시장에 가서 과일을 사요?

시장에서 과일을 사요 focuses solely on performing the buying action at the market. 시장에 가서 과일을 사요 literally describes going to the market and then buying fruit, so it emphasizes both the movement and the purchase.

What about 주마다—can I say 주마다 과일을 사요 instead of 매주?

Yes. 주마다 also means every week, using the particle -마다 meaning each or every. 매주 and 주마다 are interchangeable in most contexts. Avoid 매주마다, though, because it redundantly repeats every week.