To have a secret plan or idea.
Tener un plan o idea secreta. (Tener un plan o idea secreta.)
"Don’t worry, he has something up his sleeve for the project."
"No te preocupes, él tiene algo bajo la manga para el proyecto." (No te preocupes, él **tiene algo bajo la manga** para el proyecto.)
to start behaving in an unusual or uncontrolled way
to do something secretly or deceitfully against someone
To exert effort or work hard at something.
to stop being interested in something
someone who has similar interests or feelings
to criticize someone harshly