1. Syntax: Ada and Swift have different syntactical structures. Ada follows a more traditional syntax similar to that of Pascal, while Swift adopts a more modern and concise syntax inspired by languages like C and Objective-C. For example, in declaring variables, Ada requires the use of the "type" keyword, while Swift uses type inference.
2. Memory Management: Ada uses manual memory management, where the programmer is responsible for explicitly allocating and deallocating memory using mechanisms like pointers and deallocation statements. In contrast, Swift utilizes automatic reference counting (ARC) for memory management, where memory is automatically allocated and deallocated based on the lifespan of objects.
3. Concurrency: Ada provides built-in support for tasking and concurrent programming with its tasking constructs and synchronization primitives. On the other hand, Swift does not have built-in support for tasking and concurrency, although it offers mechanisms like Grand Central Dispatch (GCD) and Operation Queues for concurrent programming.
4. Platform Compatibility: Ada is designed to be highly portable and can be used on a wide range of platforms, including various embedded systems and real-time environments. Meanwhile, Swift is primarily targeted for the Apple ecosystem, working seamlessly with iOS, macOS, watchOS, and tvOS platforms.
5. Error Handling: Ada uses exception handling as its primary mechanism for dealing with errors, allowing the programmer to catch and handle exceptions raised during the execution. In contrast, Swift utilizes a combination of error handling using try-catch blocks and optional types to handle potential errors.
6. Standard Libraries: Ada has a comprehensive set of standard libraries that cover various domains, including numerical computation, networking, and database access, among others. Swift, being a relatively newer language, has a growing standard library focused on providing fundamental functionalities for its target platforms.

In Summary, Ada and Swift have key differences in syntax, memory management, concurrency support, platform compatibility, error handling mechanisms, and the availability of standard libraries.