--- a/docs/obs-concept.rst
+++ b/docs/obs-concept.rst
@@ -170,7 +170,7 @@
 as conflicting changes on file.
 
 
-Detecting and solving tricky situation
+Detecting and solving tricky situations
 ======================================
 
 History rewriting can lead to complex situations. Obsolete marker introduce a
@@ -213,9 +213,9 @@
 * Pull a changeset based of an old version of a changeset [#]_.
 
 * Use a partial rewriting operation. For example amend on a changeset with
-  children.
+  children .
 
-*Non-obsolete* changeset based on *obsolete* one are said **unstable**
+*Non-obsolete* changeset based on *obsolete* one are called **unstable**
 
 .. figure:: ./figures/error-unstable.*
 
@@ -233,7 +233,7 @@
 the user of even carry them out for him.
 
 
-XXX details automatic resolution for
+XXX details on automatic resolution for
 
 * movement
 
@@ -243,17 +243,17 @@
 
 
 .. [#] For this to happen one needs to explicitly enable exchange of draft
-       changeset. See phase help for details.
+       changesets. See phase help for details.
 
 The two part of the obsolete set
 --------------------------------
 
-The previous section show that it could be two kinds of *obsolete* changeset:
+The previous section show that there can be two kinds of an *obsolete* changeset:
 
 
-* *obsolete* changeset with no or *obsolete* only descendants, said **extinct**.
+* an *obsolete* changeset with no or *obsolete* only descendants is called **extinct**.
 
-* *obsolete* changeset with *unstable* descendants, said **suspended**.
+* an *obsolete* changeset with *unstable* descendants is called **suspended**.
 
 
 .. figure:: ./figures/error-extinct.*
@@ -266,46 +266,46 @@
 
 
 Because nothing outside the obsolete set default on *extinct* changesets, they
-can be safely hidden in the UI and even garbage collected. *Suspended* changeset
-have to stay visible and available until they unstable descendant are rewritten
-in stable version.
+can be safely hidden in the UI and even garbage collected. *Suspended* changesets
+have to stay visible and available until their unstable descendant are rewritten
+into stable version.
 
 
-Conflicting rewriting
+Conflicting rewrites
 ---------------------
 
 If people start to concurrently edit the same part of the history they will
-likely meet conflicting situation when a changeset have been rewritten in two
-different versions.
+likely meet conflicting situations when a changeset has been rewritten in two
+different ways.
 
 
 .. figure:: ./figures/error-conflicting.*
 
-    Conflicting rewriting of `A` into `A'` and `A''`
+    Conflicting rewrite of `A` into `A'` and `A''`
 
-This kind of conflict is easy to detect with obsolete marker because an obsolete
-changeset have more than one new version. It may be seen as the multiple heads
-case Mercurial warn you about on pull. It is resolved the same way by a merge of
+This kind of conflict is easy to detect with obsolete markers, because an obsolete
+changeset can have more than one new version. It may be seen as the multiple heads
+case which Mercurial warns you about on pull. It is resolved the same way by a merge of
 A' and A'' that will keep the same parent than `A'` and `A''` with two obsolete
 markers pointing to both `A` and `A'`
 
 .. warning::  TODO: Add a schema of the resolution. (merge A' and A'' with A as
               ancestor and graft the result of A^)
 
-Allowing multiple new changesets to obsolete a single one allow to distinct a
-splitted changeset from history rewriting conflict.
+Allowing multiple new changesets to obsolete a single one allows to differenciate
+split changesets from history rewriting conflicts.
 
 Reliable history
 ----------------
 
-Obsolete marker really help to smooth rewriting operation process. However they
+Obsolete marker help to smooth rewriting operation process. However they
 do not change the fact that **you should only rewrite the mutable part of the
-history**. The phase concept enforce this rules by explicitly defining a
-public immutable set of changeset. Rewriting operation refuse to work on
-public changeset, but they is still some corner case where changesets
-rewritten in the past are made public.
+history**. The phase concept enforces this rule by explicitly defining a
+public immutable set of changesets. Rewriting operations refuse to work on
+public changesets, but there are still some corner cases where previously rewritten changesets
+are made public.
 
-Special rules apply for obsolete marker pointing to public changeset
+Special rules apply for obsolete markers pointing to public changesets
 
 * Public changesets are excluded from the obsolete set (public changeset are
   never hidden or candidate to garbage collection)
@@ -325,11 +325,11 @@
 Conclusion
 ==========
 
-Obsolete marker is a powerful concept that allow mercurial to safely handle
+The obsolete marker is a powerful concept that allows mercurial to safely handle
 history rewriting operations. It is a new type of relation between Mercurial
-changesets that track the result of history rewriting operations.
+changesets which tracks the result of history rewriting operations.
 
-This concept is simple to define and provides a very solid base to:
+This concept is simple to define and provides a very solid base for:
 
 
 - Very fast history rewriting operations,
@@ -338,11 +338,11 @@
 
 - clean final history,
 
-- share and collaborate on mutable part of the history,
+- sharing and collaborating on the mutable part of the history,
 
-- gracefully handle history rewriting conflict,
+- gracefully handling history rewriting conflicts,
 
-- allows various history rewriting UI to collaborate with a underlying common API.
+- various history rewriting UI’s collaborating with an underlying common API.
 
 .. list-table:: Comparison on solution [#]_
    :header-rows: 1