Вежливый продавец разменял мне купюру.

The polite seller broke a banknote for me.

Breakdown of Вежливый продавец разменял мне купюру.

• мне: me
• купюра: banknote
• вежливый: polite
• разменять: to break (a banknote) / to change (money)
• продавец: seller

Questions & Answers about Вежливый продавец разменял мне купюру.

Why is вежливый in the form вежливый, and not something else?

Because it agrees with продавец (the noun it describes). Продавец is masculine, singular, nominative, so the adjective is also masculine, singular, nominative: вежливый продавец.
(If it were feminine: вежливая продавщица; plural: вежливые продавцы.)

What grammatical case is продавец here, and how do I know?

Продавец is nominative singular because it is the subject (the person doing the action). In Russian, the “doer” of the verb is typically in the nominative case, and the verb разменял agrees with it in gender/number in the past tense.

Why is the verb разменял in this form?

Разменял is:

• past tense (the action happened)
• masculine singular (because the subject продавец is treated as masculine singular)
• perfective aspect (completed action)

If the subject were feminine: разменяла. If plural: разменяли.

What does the ending -л in разменял indicate?

In past tense, many Russian verbs use -л as part of the past tense marker (historically derived). Then you add gender/number endings:

• masculine: разменял
• feminine: разменяла
• neuter: разменяло
• plural: разменяли

Why is мне used here, and what case is it?

Мне is dative case of я (мне = “to me / for me”). With разменять, Russian often uses the dative to show the person who benefits from the action (a “benefactive dative”): the seller changed the banknote for me.

Could I say для меня instead of мне?

Sometimes, but it changes the feel. Мне is the normal, compact way to express “for me” with many everyday actions, including services. Для меня is more explicit and can sound more contrastive or emphatic (like “for me (not for someone else)”), or it can refer more to purpose than to a simple service. In this sentence, мне is the most natural.

Why is купюру in the form купюру?

Because it’s the direct object of the verb разменял (what was changed), so it’s in the accusative singular. Купюра is feminine, and feminine accusative singular typically ends in -у/-ю:

• nominative: купюра
• accusative: купюру

Does разменять always take this pattern: разменять + (кого?) + (что?)?

The typical pattern is:

• разменять (что?) = to change (a bill/coin), direct object in accusative
  Optionally:
• разменять (кому?) (что?) = to change something for someone, with the person in dative (мне)
  Often you also add what you changed it into:
• разменять купюру на мелочь (accusative + на
  • accusative)

What’s the difference between разменял and разменивал?

It’s aspect:

• разменял (perfective) = changed it successfully / completed, one whole action
• разменивал (imperfective) = was changing / used to change / was in the process, or describing repeated actions

In this sentence, a completed service is meant, so разменял fits.

Is the word order fixed? Could I move words around?

Russian word order is flexible because case endings show roles. Вежливый продавец разменял мне купюру is neutral. You can move parts to change emphasis:

• Купюру мне разменял вежливый продавец (emphasis on купюру)
• Мне разменял купюру вежливый продавец (emphasis on мне) The meaning stays basically the same, but the focus changes.

Does продавец always mean a male seller?

Grammatically it’s masculine, but it can refer to a seller of any gender in many contexts (especially in job titles). If you want an explicitly feminine noun, Russian often uses продавщица, though usage varies by region/style.

Where is the stress in these words?

Common stresses here are:

• вежли́вый
• прода́вец
• разменя́л
• мне (usually unstressed but pronounced clearly)
• купю́ру