A person sneaks when trying to be quiet or when trying to do something without other people noticing. This verb has regular and irregular forms. The irregular form is common in standard, spoken English.
simple
past
past participle
sneak
sneaked / snuck
sneaked / snuck
Jerry tried to sneak into the classroom late without the teacher noticing.
He snuck into the classroom. (past tense)
There’s a cat sneaking around our house looking for mice.
A burglar snuck into our office last night and stole three computers.
The little girl snuck a cookie out of the cookie jar without asking her mother if it was okay.
Rachel often sneaks out of the house at night without her parents’ knowledge.
A spy for the CIA snuck into the offices of a foreign government and stole some important documents.
On a Friday afternoon, employees might try to sneak out of the office early to get an early start on the weekend.
He’s sneaking out of the office early.
Use "sneak up" when a person or a thing approaches without you realizing it.
The time really snuck up on me.
We weren’t prepared for the meeting. It snuck up on us.
Ahmed likes to sneak up on people in order to surprise them.
Please, don’t sneak up on me like that!
The word "sneaky" is an adjective:
Pete is a very sneaky guy. Few people trust him.
He seems very sneaky.
Cindy stopped hanging out with Samantha because she’s so sneaky about everything.
