The original sentence is: "A sea turtle is easy to draw: a big oval for the shell, smaller ovals for the legs and a head."
This sentence is mostly correct, but it can be improved slightly for clarity and punctuation. Here's a corrected version:
"A sea turtle is easy to draw: use a big oval for the shell, smaller ovals for the legs, and an oval for the head."
Explanation:
- Adding "use" helps clarify the instruction.
- Adding a comma before "and" improves readability in the list.
- Replacing "a head" with "an oval for the head" makes the description more consistent with the earlier parts (which specify shapes).
Alternatively, if you want to keep it simpler, you might say:
"A sea turtle is easy to draw: a big oval for the shell, smaller ovals for the legs, and an oval for the head."
Note the comma before "and" in the list and the consistent use of shapes for all parts.