diff --git a/helix-core/src/movement.rs b/helix-core/src/movement.rs
index 0f3ddd1c5..c309844cf 100644
--- a/helix-core/src/movement.rs
+++ b/helix-core/src/movement.rs
@@ -1073,6 +1073,178 @@ mod test {
         }
     }
 
+    #[test]
+    fn test_behaviour_when_moving_to_start_of_next_sub_words() {
+        let tests = [
+            (
+                "NextSubwordStart",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 4)),
+                    (1, Range::new(4, 4), Range::new(4, 11)),
+                ],
+            ),
+            (
+                "next_subword_start",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 5)),
+                    (1, Range::new(4, 4), Range::new(5, 13)),
+                ],
+            ),
+            (
+                "Next_Subword_Start",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 5)),
+                    (1, Range::new(4, 4), Range::new(5, 13)),
+                ],
+            ),
+            (
+                "NEXT_SUBWORD_START",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 5)),
+                    (1, Range::new(4, 4), Range::new(5, 13)),
+                ],
+            ),
+            (
+                "next subword start",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 5)),
+                    (1, Range::new(4, 4), Range::new(5, 13)),
+                ],
+            ),
+            (
+                "Next Subword Start",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 5)),
+                    (1, Range::new(4, 4), Range::new(5, 13)),
+                ],
+            ),
+            (
+                "NEXT SUBWORD START",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 5)),
+                    (1, Range::new(4, 4), Range::new(5, 13)),
+                ],
+            ),
+            (
+                "next__subword__start",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 6)),
+                    (1, Range::new(4, 4), Range::new(4, 6)),
+                    (1, Range::new(5, 5), Range::new(6, 15)),
+                ],
+            ),
+            (
+                "Next__Subword__Start",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 6)),
+                    (1, Range::new(4, 4), Range::new(4, 6)),
+                    (1, Range::new(5, 5), Range::new(6, 15)),
+                ],
+            ),
+            (
+                "NEXT__SUBWORD__START",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 6)),
+                    (1, Range::new(4, 4), Range::new(4, 6)),
+                    (1, Range::new(5, 5), Range::new(6, 15)),
+                ],
+            ),
+        ];
+
+        for (sample, scenario) in tests {
+            for (count, begin, expected_end) in scenario.into_iter() {
+                let range = move_next_sub_word_start(Rope::from(sample).slice(..), begin, count);
+                assert_eq!(range, expected_end, "Case failed: [{}]", sample);
+            }
+        }
+    }
+
+    #[test]
+    fn test_behaviour_when_moving_to_end_of_next_sub_words() {
+        let tests = [
+            (
+                "NextSubwordEnd",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 4)),
+                    (1, Range::new(4, 4), Range::new(4, 11)),
+                ],
+            ),
+            (
+                "next subword end",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 4)),
+                    (1, Range::new(4, 4), Range::new(4, 12)),
+                ],
+            ),
+            (
+                "Next Subword End",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 4)),
+                    (1, Range::new(4, 4), Range::new(4, 12)),
+                ],
+            ),
+            (
+                "NEXT SUBWORD END",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 4)),
+                    (1, Range::new(4, 4), Range::new(4, 12)),
+                ],
+            ),
+            (
+                "next_subword_end",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 4)),
+                    (1, Range::new(4, 4), Range::new(4, 12)),
+                ],
+            ),
+            (
+                "Next_Subword_End",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 4)),
+                    (1, Range::new(4, 4), Range::new(4, 12)),
+                ],
+            ),
+            (
+                "NEXT_SUBWORD_END",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 4)),
+                    (1, Range::new(4, 4), Range::new(4, 12)),
+                ],
+            ),
+            (
+                "next__subword__end",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 4)),
+                    (1, Range::new(4, 4), Range::new(4, 13)),
+                    (1, Range::new(5, 5), Range::new(5, 13)),
+                ],
+            ),
+            (
+                "Next__Subword__End",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 4)),
+                    (1, Range::new(4, 4), Range::new(4, 13)),
+                    (1, Range::new(5, 5), Range::new(5, 13)),
+                ],
+            ),
+            (
+                "NEXT__SUBWORD__END",
+                vec![
+                    (1, Range::new(0, 0), Range::new(0, 4)),
+                    (1, Range::new(4, 4), Range::new(4, 13)),
+                    (1, Range::new(5, 5), Range::new(5, 13)),
+                ],
+            ),
+        ];
+
+        for (sample, scenario) in tests {
+            for (count, begin, expected_end) in scenario.into_iter() {
+                let range = move_next_sub_word_end(Rope::from(sample).slice(..), begin, count);
+                assert_eq!(range, expected_end, "Case failed: [{}]", sample);
+            }
+        }
+    }
+
     #[test]
     fn test_behaviour_when_moving_to_start_of_next_long_words() {
         let tests = [
@@ -1242,6 +1414,92 @@ mod test {
         }
     }
 
+    #[test]
+    fn test_behaviour_when_moving_to_start_of_previous_sub_words() {
+        let tests = [
+            (
+                "PrevSubwordEnd",
+                vec![
+                    (1, Range::new(13, 13), Range::new(14, 11)),
+                    (1, Range::new(11, 11), Range::new(11, 4)),
+                ],
+            ),
+            (
+                "prev subword end",
+                vec![
+                    (1, Range::new(15, 15), Range::new(16, 13)),
+                    (1, Range::new(12, 12), Range::new(13, 5)),
+                ],
+            ),
+            (
+                "Prev Subword End",
+                vec![
+                    (1, Range::new(15, 15), Range::new(16, 13)),
+                    (1, Range::new(12, 12), Range::new(13, 5)),
+                ],
+            ),
+            (
+                "PREV SUBWORD END",
+                vec![
+                    (1, Range::new(15, 15), Range::new(16, 13)),
+                    (1, Range::new(12, 12), Range::new(13, 5)),
+                ],
+            ),
+            (
+                "prev_subword_end",
+                vec![
+                    (1, Range::new(15, 15), Range::new(16, 13)),
+                    (1, Range::new(12, 12), Range::new(13, 5)),
+                ],
+            ),
+            (
+                "Prev_Subword_End",
+                vec![
+                    (1, Range::new(15, 15), Range::new(16, 13)),
+                    (1, Range::new(12, 12), Range::new(13, 5)),
+                ],
+            ),
+            (
+                "PREV_SUBWORD_END",
+                vec![
+                    (1, Range::new(15, 15), Range::new(16, 13)),
+                    (1, Range::new(12, 12), Range::new(13, 5)),
+                ],
+            ),
+            (
+                "prev__subword__end",
+                vec![
+                    (1, Range::new(17, 17), Range::new(18, 15)),
+                    (1, Range::new(13, 13), Range::new(14, 6)),
+                    (1, Range::new(14, 14), Range::new(15, 6)),
+                ],
+            ),
+            (
+                "Prev__Subword__End",
+                vec![
+                    (1, Range::new(17, 17), Range::new(18, 15)),
+                    (1, Range::new(13, 13), Range::new(14, 6)),
+                    (1, Range::new(14, 14), Range::new(15, 6)),
+                ],
+            ),
+            (
+                "PREV__SUBWORD__END",
+                vec![
+                    (1, Range::new(17, 17), Range::new(18, 15)),
+                    (1, Range::new(13, 13), Range::new(14, 6)),
+                    (1, Range::new(14, 14), Range::new(15, 6)),
+                ],
+            ),
+        ];
+
+        for (sample, scenario) in tests {
+            for (count, begin, expected_end) in scenario.into_iter() {
+                let range = move_prev_sub_word_start(Rope::from(sample).slice(..), begin, count);
+                assert_eq!(range, expected_end, "Case failed: [{}]", sample);
+            }
+        }
+    }
+
     #[test]
     fn test_behaviour_when_moving_to_start_of_previous_long_words() {
         let tests = [
@@ -1505,6 +1763,92 @@ mod test {
         }
     }
 
+    #[test]
+    fn test_behaviour_when_moving_to_end_of_previous_sub_words() {
+        let tests = [
+            (
+                "PrevSubwordEnd",
+                vec![
+                    (1, Range::new(13, 13), Range::new(14, 11)),
+                    (1, Range::new(11, 11), Range::new(11, 4)),
+                ],
+            ),
+            (
+                "prev subword end",
+                vec![
+                    (1, Range::new(15, 15), Range::new(16, 12)),
+                    (1, Range::new(12, 12), Range::new(12, 4)),
+                ],
+            ),
+            (
+                "Prev Subword End",
+                vec![
+                    (1, Range::new(15, 15), Range::new(16, 12)),
+                    (1, Range::new(12, 12), Range::new(12, 4)),
+                ],
+            ),
+            (
+                "PREV SUBWORD END",
+                vec![
+                    (1, Range::new(15, 15), Range::new(16, 12)),
+                    (1, Range::new(12, 12), Range::new(12, 4)),
+                ],
+            ),
+            (
+                "prev_subword_end",
+                vec![
+                    (1, Range::new(15, 15), Range::new(16, 12)),
+                    (1, Range::new(12, 12), Range::new(12, 4)),
+                ],
+            ),
+            (
+                "Prev_Subword_End",
+                vec![
+                    (1, Range::new(15, 15), Range::new(16, 12)),
+                    (1, Range::new(12, 12), Range::new(12, 4)),
+                ],
+            ),
+            (
+                "PREV_SUBWORD_END",
+                vec![
+                    (1, Range::new(15, 15), Range::new(16, 12)),
+                    (1, Range::new(12, 12), Range::new(12, 4)),
+                ],
+            ),
+            (
+                "prev__subword__end",
+                vec![
+                    (1, Range::new(17, 17), Range::new(18, 13)),
+                    (1, Range::new(13, 13), Range::new(13, 4)),
+                    (1, Range::new(14, 14), Range::new(15, 13)),
+                ],
+            ),
+            (
+                "Prev__Subword__End",
+                vec![
+                    (1, Range::new(17, 17), Range::new(18, 13)),
+                    (1, Range::new(13, 13), Range::new(13, 4)),
+                    (1, Range::new(14, 14), Range::new(15, 13)),
+                ],
+            ),
+            (
+                "PREV__SUBWORD__END",
+                vec![
+                    (1, Range::new(17, 17), Range::new(18, 13)),
+                    (1, Range::new(13, 13), Range::new(13, 4)),
+                    (1, Range::new(14, 14), Range::new(15, 13)),
+                ],
+            ),
+        ];
+
+        for (sample, scenario) in tests {
+            for (count, begin, expected_end) in scenario.into_iter() {
+                let range = move_prev_sub_word_end(Rope::from(sample).slice(..), begin, count);
+                assert_eq!(range, expected_end, "Case failed: [{}]", sample);
+            }
+        }
+    }
+
     #[test]
     fn test_behaviour_when_moving_to_end_of_next_long_words() {
         let tests = [