Learn Swedish: Jag betalar för de här kläderna i kassan. - I am paying for these clothes at the checkout.

In Swedish, when you use den här, det här, or de här (this/these), the noun that follows must always be in the definite form. Kläder means clothes, so you must use the definite form kläderna (the clothes) together with de här.

How do you pronounce de in de här?

Even though it is spelled de, it is pronounced like dom in spoken Swedish. So you will hear native speakers say dom här.

Why does the sentence use i kassan instead of a word for at?

Prepositions rarely translate perfectly between languages. In Swedish, you say you pay i kassan (literally in the checkout or in the cash register) rather than at it.

Is there a way to say I am paying instead of just I pay?

Swedish does not have a separate continuous tense like English does. The single verb betalar covers both I pay and I am paying.