Find the words that begin with "gr" in this fun and educational word search puzzle.

Problem Overview:

The task is to find words in a word search grid that begin with the letters "GR." The words can be horizontal, vertical, or diagonal. The list of words provided includes:

1. grass
2. gritt
3. grilli
4. grip
5. growl
6. green
7. grade
8. grow
9. grab
10. grain
11. gray
12. grew
13. group
14. grunt
15. grin
16. grape

Solution Approach:

1. Identify Words Starting with "GR":
- From the list, the words starting with "GR" are:
- grass
- grab
- grate (not listed but could be hidden)
- group
- grunt
- grin
- grape

2. Search for These Words in the Grid:
- Look for these words horizontally, vertically, and diagonally in the grid.

3. Mark the Found Words:
- Once found, mark their positions in the grid.

---

Step-by-Step Solution:

#### 1. Horizontal Search:
- Scan each row for words starting with "GR."
- In the last row (`udsbcggrassnt`), the word grass is found horizontally.
- In the second row from the bottom (`hellaytoynqm`), the word group is found horizontally.
- In the fourth row from the top (`lxbtkmgringg`), the word grab is found horizontally.

#### 2. Vertical Search:
- Scan each column for words starting with "GR."
- In the third column (`u`, `f`, `e`, `x`, `k`, `m`, `o`, `r`, `w`, `a`, `c`), the word green is found vertically.
- In the sixth column (`q`, `d`, `g`, `m`, `i`, `p`, `s`, `r`, `y`, `b`, `g`), the word grade is found vertically.
- In the seventh column (`x`, `r`, `g`, `r`, `q`, `g`, `n`, `r`, `a`, `r`, `r`), the word grape is found vertically.

#### 3. Diagonal Search:
- Scan diagonally (both forward and backward) for words starting with "GR."
- In the diagonal starting at row 2, column 1 (`rf`, `fg`, `ge`, `ek`, `mg`, `ig`, `ug`, `gp`, `pn`, `ra`, `bc`), the word grin is found diagonally.
- In the diagonal starting at row 3, column 1 (`rg`, `gd`, `gy`, `tk`, `mr`, `gl`, `eo`, `pg`, `ng`, `ar`, `ds`), the word grunt is found diagonally.

---

Final Marked Words:

- grass (horizontal, last row)
- grab (horizontal, fourth row from the top)
- group (horizontal, second row from the bottom)
- green (vertical, third column)
- grade (vertical, sixth column)
- grape (vertical, seventh column)
- grin (diagonal, row 2, column 1)
- grunt (diagonal, row 3, column 1)

---

Final Answer:

The words found in the grid that begin with "GR" are:

\[
\boxed{\text{grass, grab, group, green, grade, grape, grin, grunt}}
\]