diff --git a/source/Collection_Data_Types.rst b/source/Collection_Data_Types.rst
index df267756326fb7ecbef968367cf77b1753f18c84..5fc4b1adb515eaad388ebe41fbce18a8c41f9fea 100644
--- a/source/Collection_Data_Types.rst
+++ b/source/Collection_Data_Types.rst
@@ -360,11 +360,11 @@ In the first algorithm.
 
 | In the second algorithm we read the sequence only once
 =======
-In the first alogrithm.
+In the first algorithm.
 
 | we first compute all kmers we generate 4\ :sup:`kmer length`
-| then we count the occurence of each kmer in the sequence
-| so for each kmer we read all the sequence so the algorith is in O( 4\ :sup:`kmer length` * ``sequence length``)
+| then we count the occurrence of each kmer in the sequence
+| so for each kmer we read all the sequence so the algorithm is in O( 4\ :sup:`kmer length` * ``sequence length``)
 
 | In the secon algorithm we read the sequence only once
 >>>>>>> e986fb63db27fe063adb907bfb916dbb79c5db9b
@@ -448,7 +448,7 @@ pseudocode:
 """""""""""
 
 | *function reverse_comp(sequence)*
-|     *complement <- establish a correpondance and each base and its complement*
+|     *complement <- establish a correspondance and each base and its complement*
 |     *rev_seq <- revert the sequence*
 |     *rev_comp <- empty*
 |     *for each nt of rev_seq*