I couldn't fall asleep.

I Pronoun

— The person who is speaking or writing I am writing this, and you are reading it.

I Noun

— The ninth letter or the alphabet; previous H, next J. I is a vowel.

I Symbol

— A symbol meaning first, as in "George I" (which is said as "George the first"). — The symbol for iodine on the periodic table of elements. — The symbol for electrical current.

I Number

— This is the roman numeral for one (1). It may be written as I or i.

i Noun

— The ninth letter or the alphabet; previous H, next J. I is a vowel.

couldn't Contraction

— The contraction of "could not". He couldn't make it to work yesterday because he was sick. I couldn't believe how rude she was.

fall Verb

— When something or someone falls, it moves down quickly down through the air because nothing is holding it. It moves to a lower position because of gravity. The apple fell from the tree. The bridge is falling down. He tripped on a banana peel and fell down, hurting his leg. — When someone falls, they can mean coming down to the ground on purpose, lying with the face down. He fell to the floor and begged for mercy. — Falling is when someone or something has been defeated. The Romans fell to the Goths in 410 AD.

fall Noun

— Fall is the name for autumn used only in North America, named after the falling of leaves during the season. It is the season when the weather is getting colder, after summer and before winter. These plants are growing big and they will be ready to eat in the fall. — A fall or falls or waterfall is a part of a river where water is falling. We went to the falls to eat lunch outside and watch the water falling. — A fall is when people suffered a loss of greatness or status, such as the fall of Rome.

asleep Adjective

— If you are asleep, you are sleeping. Please be quiet. The baby's asleep. I had trouble falling asleep last night.