diff --git a/datetimes.Rmd b/datetimes.Rmd
index 44f2d5e..a2dc420 100644
--- a/datetimes.Rmd
+++ b/datetimes.Rmd
@@ -73,7 +73,7 @@ These functions also take unquoted numbers. This is the most concise way to crea
 ymd(20170131)
 ```
 
-`ymd()` and friends create dates. To create a date-time, add an underscore and and one or more of "h", "m", and "s" to the name of the parsing function:
+`ymd()` and friends create dates. To create a date-time, add an underscore and one or more of "h", "m", and "s" to the name of the parsing function:
 
 ```{r}
 ymd_hms("2017-01-31 20:11:59")
diff --git a/vectors.Rmd b/vectors.Rmd
index 3d9723d..221a031 100644
--- a/vectors.Rmd
+++ b/vectors.Rmd
@@ -308,7 +308,7 @@ There are four types of thing that you can subset a vector with:
     x[c(3, 2, 5)]
     ```
     
-    By repeating a position, you can actually make an longer output than 
+    By repeating a position, you can actually make a longer output than 
     input:
     
     ```{r}