fixup! middle-1/haskell: fix some questions, add new ones

Author: antonkalinin-ml

backend/middle-1/haskell.md

@@ -128,21 +128,21 @@ How can we bundle Pattern Synonyms with datatypes in export and import lists?
 ## Laziness
 
 * Describe the process of evaluating a thunk and storing the evaluated value.
-* After a thunk is fully evaluated, will the GHC runtime evaluate it again?
+* After a thunk is fully evaluated, can the GHC runtime evaluate it again?
 * What is a black hole and what problem does it solve?
-* What kind of thunks are black holes used for?
-* Enumerate cases where a thunk returning an ADT will be evaluated.
+* For what kind of thunks are black holes used?
+* Enumerate cases where a thunk returning an ADT is evaluated.
 * What is an irrefutable pattern and how does it work?
 * Where are patterns in Haskell irrefutable by default?
 * Which patterns are irrefutable:
   1. `f (Just a) = ...`
   1. `let (Just a) = ...`
   1. `where (Just a) = ...`
-  1. `g (MyType a) = ...` where `MyType` is a `newtype` declaration.
-  1. `g (MyType a) = ...` where `MyType` is a `data` declaration.
+  1. `g (N a) = ...` where `newtype N a = N a`.
+  1. `g (D a) = ...` where `data D a = D a`.
   1. `f a = ...`
   1. `f _ = ...`
-* When can irrefutable patterns be helpful? Hint: you may describe why
+* When can irrefutable patterns be useful? Hint: you may describe why
   [`Data.List.partition`](https://hackage.haskell.org/package/base-4.16.0.0/docs/src/Data.OldList.html#partition)
   uses them.
 * What does the `sprint` command do in `ghci`?