Good job looking at that sentence! Here are simple, correct ways to say it and a short explanation.
Correct sentences you can use:
- A baby kangaroo is safest in its mother's pouch. (Use this when you mean any baby kangaroo.)
- The baby kangaroo is safest in its mother's pouch. (Use this when you mean one particular baby kangaroo.)
Why these are better:
- Use a for any baby kangaroo and the for a specific one.
- We usually say "is safest" (without an extra "the") when we talk about where something feels safest.
- "its mother's pouch" is correct because "its" shows the pouch belongs to the mother kangaroo.
Both sentences need a period at the end. Great work asking about grammar!