Here's why:
* Different Structures: Sign languages have their own distinct grammar, syntax, and structure that are different from English. They use spatial relationships, facial expressions, and body movements to convey meaning in ways that spoken English doesn't.
* Unique Vocabulary: Sign languages have their own unique signs, many of which have no direct translation into English.
* Not Just "English in Signs": While some signs may resemble English words, the meaning and context are often very different. For example, the sign for "cat" in American Sign Language (ASL) is a specific handshape that doesn't resemble the word "cat" in English.
Think of sign languages as separate languages with their own rules and complexities, just like spoken languages. While there may be some similarities in concepts, they are fundamentally different systems of communication.