It sounds like you're asking about a human's nails. There are many reasons why someone's nails might be soft, including:
* Nutritional deficiencies: Lack of certain vitamins and minerals, like biotin, can affect nail health.
* Medical conditions: Certain health conditions, like thyroid disease or psoriasis, can also affect nail strength.
* Overuse of nail polish: Frequent use of nail polish removers can dry out and weaken nails.
* Trauma or injury: Biting your nails or hitting them against something can also make them soft.
If you're concerned about your own soft nails, it's best to consult a doctor or dermatologist. They can help you determine the underlying cause and recommend the best treatment.