Questions & Answers about On jest chory. Rozumiem go.
Why do we use go instead of on in the second sentence?
On means "he" and is used when he is the subject (the one doing the action), like in On jest chory. Go means "him". It is the accusative case form, which we use when he is the direct object (the one receiving the action) of the verb rozumiem (I understand).
Could I put go at the beginning and say "Go rozumiem"?
No. Short pronouns like go, cię, and mi are "weak" words that lean on other words. Because of this, they can never be the very first word in a sentence. Since the second sentence starts with the verb, the pronoun must go after it: Rozumiem go.
Where is the word for "I" in the second sentence?
In Polish, you usually drop subject pronouns like ja (I) because the verb ending already tells you who is doing the action. The -em ending on rozumiem clearly means "I understand". You would only add ja (Ja go rozumiem) if you wanted to emphasize that I understand him, even if someone else doesn't.
What if a woman is sick? Would the first sentence change?