Question:
The ruler is long, longer, longest than the pencil.
Answer:
longer
Explanation:
the answer is longer because, when we use the word "long" we are only mentioning one thing that is long, and when we use the word "longer" we are comparing a thing that is longer than the other one, and when we use the word "longest" we are comparing a thing to three or more things that is shorter to the longest one.
For example:
long
the hair of ana is long.
from the statement above, we are mentioning the hair of ana that is long and we are not comparing ana's hair to the other's hair.
longer
the hair of joy is longer than ana's hair.
from the statement above we are comparing joy's hair to ana's hair so we will use the word "longer" because, a thing is compared to the other thing, like the hairs of the joy and ana.
longest
the bamboo is the longest grass in the world.
from the statement above, we are comparing the length of the bamboo to the other grasses in the world, so we will use the word "longest" because we are comparing the bamboo grass to three or more grasses that is shorter than the bamboo grass do.
hope it helps:)