diff --git a/.ycm_extra_conf.py b/.ycm_extra_conf.py
index 86194357..5649ddcc 100644
--- a/.ycm_extra_conf.py
+++ b/.ycm_extra_conf.py
@@ -7,7 +7,7 @@ import ycm_core
 flags = [
 '-Wall',
 '-Werror',
-'-pendantic-errors',
+'-pedantic-errors',
 '-std=c++0x',
 '-fno-strict-aliasing',
 '-O3',
diff --git a/src/benchmark.cc b/src/benchmark.cc
index 2bfd19a7..91984f73 100644
--- a/src/benchmark.cc
+++ b/src/benchmark.cc
@@ -84,7 +84,7 @@ DEFINE_string(benchmark_out_format, "json",
               "The format to use for file output. Valid values are "
               "'console', 'json', or 'csv'.");
 
-DEFINE_string(benchmark_out, "", "The file to write additonal output to");
+DEFINE_string(benchmark_out, "", "The file to write additional output to");
 
 DEFINE_string(benchmark_color, "auto",
               "Whether to use colors in the output.  Valid values: "
@@ -503,7 +503,7 @@ void RunBenchmarks(const std::vector<Benchmark::Instance>& benchmarks,
   BenchmarkReporter::Context context;
   context.name_field_width = name_field_width;
 
-  // Keep track of runing times of all instances of current benchmark
+  // Keep track of running times of all instances of current benchmark
   std::vector<BenchmarkReporter::Run> complexity_reports;
 
   // We flush streams after invoking reporter methods that write to them. This
diff --git a/src/complexity.cc b/src/complexity.cc
index 88832698..b1aad695 100644
--- a/src/complexity.cc
+++ b/src/complexity.cc
@@ -65,10 +65,10 @@ std::string GetBigOString(BigO complexity) {
 
 // Find the coefficient for the high-order term in the running time, by
 // minimizing the sum of squares of relative error, for the fitting curve
-// given by the lambda expresion.
+// given by the lambda expression.
 //   - n             : Vector containing the size of the benchmark tests.
 //   - time          : Vector containing the times for the benchmark tests.
-//   - fitting_curve : lambda expresion (e.g. [](int n) {return n; };).
+//   - fitting_curve : lambda expression (e.g. [](int n) {return n; };).
 
 // For a deeper explanation on the algorithm logic, look the README file at
 // http://github.com/ismaelJimenez/Minimal-Cpp-Least-Squared-Fit
diff --git a/src/sysinfo.cc b/src/sysinfo.cc
index fdcc95bb..24ab6d6b 100644
--- a/src/sysinfo.cc
+++ b/src/sysinfo.cc
@@ -455,7 +455,7 @@ double GetCPUCyclesPerSecond() {
     std::string value;
     if (SplitIdx != std::string::npos) value = ln.substr(SplitIdx + 1);
     // When parsing the "cpu MHz" and "bogomips" (fallback) entries, we only
-    // accept postive values. Some environments (virtual machines) report zero,
+    // accept positive values. Some environments (virtual machines) report zero,
     // which would cause infinite looping in WallTime_Init.
     if (startsWithKey(ln, "cpu MHz")) {
       if (!value.empty()) {