English-Russian irregular words tester
First of all, I would architecture the data in a more readable and flexible way:

[
  {
    infinitive: "be",
    past: "was",
    participle: "been",
    russian: "быть"
  },
 {
   ...
 },
...
]


That tells me as reader a lot and leaves vast room for future changes without breaking the rest of your code.

Further, if you want to make your code readable for others (or even for yourself after a while), I would recommend to use descriptive names for your functions and variables. When I read

&lt;tr ng-show="isStage('input')"&gt;


I get no clue what the function isStage does from its name.
So I am forced to scan the rest of your code for its definition, which costs time. You could help me by giving it a name that would give me a rough idea without the need to go elsewhere.

Another thing I see is the use of $http inside controller, which is an anti-pattern. It sadly appears in many tutorials, yet it breaks one of the most fundamental principles of clean code - the single responsiblity principle. Your controller is responsible for gluing your scope (ViewModel layer) with your View, but not for pulling data from your Model layer. That is the job of a dedicated Service.