Eczacı reçeteyi aldı, sonra ilaçları seçti.

In Turkish, a definite direct object (a specific item) takes the accusative case suffix -i. Here:

• Reçete (prescription) is definite → needs accusative
• Because the word ends in a vowel, we insert the buffer consonant y to avoid two vowels in a row
  Result: reçete+y+i = reçeteyi (“the prescription”).

This word shows plural plus definite object:

• Stem ilaç (medicine) + plural suffix -lar (vowel harmony with “a”) → ilaçlar
• Add accusative -ı (no buffer since “ç” is a consonant) → ilaçlar+ı = ilaçları (“the medicines”).

Turkish is a pro-drop (null-subject) language. The verb endings tell you who is acting:

• aldı ends in -dı, marking 3rd person singular past
• seçti ends in -ti, also 3rd person singular past
  Thus “he/she” is understood and not stated.

Sonra means “then” or “afterwards,” linking two actions in time.

• It functions like a time-sequence adverb
• You can place it at the start of the second clause or right after a comma
  The comma isn’t grammatically required but often used to signal a pause:
  Eczacı reçeteyi aldı, sonra ilaçları seçti.

Both verbs use the simple past suffix -DI (with vowel harmony: -dı/-di/-du/-dü). The initial consonant changes by voicing assimilation:

• After a voiced consonant (l in al-) it becomes -dı → aldı
• After a voiceless consonant (ç in seç-) it becomes -tı → seçti

Turkish’s default word order is SOV:

• Subject (Eczacı)
• Object (reçeteyi / ilaçları)
• Verb (aldı / seçti)
  You can shift elements for emphasis, but verbs typically stay at the end of their clause.

Yes. Turkish allows flexibility for focus or style:

• Emphasize the time: Sonra eczacı reçeteyi aldı.
• Emphasize the medicines: İlaçları eczacı seçti.
• Split into two sentences or add ve (“and”) if you prefer:
  Eczacı reçeteyi aldı. Sonra ilaçları seçti.
  Eczacı reçeteyi aldı ve sonra ilaçları seçti.