I added the correct lines of code for the functions that wrote the letters H, I, L, and N. I made sure all 4 of my letters worked then submitted once.

I was feeling confused at the beginning because I was not sure how to start off this problem set.  I then got a piece of paper and started writing down the letters I wanted to draw.  This helped me realize when I needed to turn the pen and how many degrees to turn for the turtle.  I was frustrated before I hand wrote the letters then I was happy after as it correctly worked in python.  I was excited to see that my letters were working.

typeface.py

@@ -12,6 +12,11 @@
 from turtle import *
 from math import sqrt
 
+def fly(distance):
+    penup()
+    forward(distance)
+    pendown()
+
 def draw_letter_a(unit):
     pass
 
@@ -33,11 +38,37 @@ def draw_letter_f(unit):
 def draw_letter_g(unit):
     pass
 
-def draw_letter_h(unit):
-    pass
+def draw_letter_h(size):
+    left(90)
+    forward(size*2)
+    left(180)
+    fly(size)
+    left(90)
+    forward(size*2)
+    left(90)
+    fly(size)
+    left(180)
+    forward(size*2)
+    right(90)
+    fly(size*2)
+    left(180)
 
-def draw_letter_i(unit):
-    pass
+def draw_letter_i(size):
+    forward(size*2)
+    left(180)
+    fly(size)
+    right(90)
+    forward(size*2)
+    left(90)
+    forward(size)
+    left(180)
+    fly(size)
+    forward(size)
+    right(90)
+    fly(size*2)
+    right(90)
+    fly(size*2)
+    right(180)
 
 def draw_letter_j(unit):
     pass
@@ -45,14 +76,32 @@ def draw_letter_j(unit):
 def draw_letter_k(unit):
     pass
 
-def draw_letter_l(unit):
-    pass
+def draw_letter_l(size):
+    left(90)
+    fly(size*2)
+    left(180)
+    forward(size*2)
+    left(90)
+    forward(size*2)
+    left(180)
+    fly(size*2)
+    right(180)
 
 def draw_letter_m(unit):
     pass
 
-def draw_letter_n(unit):
-    pass
+def draw_letter_n(size):
+    left(90)
+    forward(size*2)
+    right(135)
+    forward(size*2*sqrt(2))
+    left(135)
+    forward(size*2)
+    left(180)
+    fly(size*2)
+    right(90)
+    fly(size*2)
+    left(180)
 
 def draw_letter_o(unit):
     pass
@@ -69,9 +118,10 @@ def draw_letter_r(unit):
 def draw_letter_s(unit):
     pass
 
-def draw_letter_t(unit):
+def draw_letter_t(size):
     pass
 
+
 def draw_letter_u(unit):
     pass