DONNY: 1. I went to a sauna with my family on last Sunday.
CORRECT: 1. I went to a sauna with my family last Sunday.

EXPLANATION: There's no need to use the preposition "on" as a time indicator. The word "last" is enough.

>>>

DONNY: 2. I want to became a gourmet when I grown up.
CORRECT: 2. I want to became a gourmet when I grow up.

EXPLANATION: The idiom "grow up" means "to become mature; to become adult."

>>>

DONNY: 3. I don't eat blackfast, I am famished.
CORRECT: 3. I didn't eat breakfast so, I am famished.

EXPLANATION: Be mindful of your spelling. Also, use conjunctions to link the sentences together.

>>>

DONNY: 4. I want to have duplicate machine.
CORRECT: 4. I want to have a duplicate machine.

EXPLANATION: Use the appropriate article, ex. a, an, the.

Alternative sentence:

CORRECT: 4. I want to have a cloning machine.

EXPLANATION: If you are referring to the machine that can make an exact copy of someone (just like in movies), then we call it a "cloning machine".

>>>

DONNY: 5. I grin when I feel happy.

*** CORRECT! GOOD JOB! ***

>>>

Hello, Donny! Thank you for submitting your homework! I'm impressed with the sentences you came up with! Keep it up!

I look forward to reading your next composition! I'll see you on Monday! Have a great weekend and take care always!

Always cheering you on,
Teacher Kate