Apply suggestions from code review

Co-authored-by: sandcha <[email protected]>

source/simulate/index.md

@@ -9,7 +9,7 @@ analyse-simulation
 profile-simulation
 ```
 
-To calculate Tax and Benefit System variables relating to people's situations, you need to create and run a _Simulation_.
+To calculate Tax and Benefit System variables relating to populations' situations, you need to create and run a _Simulation_.
 
 OpenFisca will work the same if there is one person, seven, or seven million in the modelled situation.
 
@@ -21,6 +21,6 @@ In this section the focus is on simulations and the two approaches that can be t
 - [test cases](./run-simulation.md#test-cases): that utilise small structured data for input,
 - [bulk data](./run-simulation.md#data): in the form of aggregated data, CSV files, etc.
 
-It's also possible to extend _Simulations_ by defining an axis which is covered in detail in the section [Replication a situation along axes](./replicate-simulation-inputs.md).
+It's also possible to extend _Simulations_ by defining an axis which is covered in detail in the section [Replicating a situation along axes](./replicate-simulation-inputs.md).
 
 When running Simulations it is also possible to activate the [`trace` feature](./analyse-simulation.md) which provides a way to analyse how the simulation achieved its results. Similarly there are options to trouble-shoot [Simulation performance](./profile-simulation.md).

source/simulate/replicate-simulation-inputs.md

@@ -5,8 +5,7 @@ Further to the two ways of populating a Simulation object with data:
 - either describe a [small population](./run-simulation.md#test-cases) with fine control over input variables and over the relationship between individuals and group entities;
 - or provide [inputs in bulk](./run-simulation.md#data), typically using tabular data (CSV, Excel, etc.)
 
-a third possibility also exists. 
-Suitable for small-scale situations such as test cases; it is possible to generate a number of "copies" of this situation, in which one or more variables of your choice take on a range of values.
+a third possibility also exists. Suitable for small-scale situations such as test cases; it is possible to generate a number of "copies" of this situation, in which one or more variables of your choice take on a range of values.
 
 The following example does this by adding an "axes" entry to a test case:
 
@@ -165,7 +164,7 @@ Note the difference in nesting; there is no longer an inner set of two axes, but
 64
 ```
 
-Why? Because `age` and `salary` are varying independently and each axis results in multiplying by 4 the original population of 4. This resultS in 4 times 4 times 4 individuals, equalling 64.
+Why? Because `age` and `salary` are varying independently and each axis results in multiplying by 4 the original population of 4. This results in 4 times 4 times 4 individuals, equalling 64.
 
 The results are as follows: