“Frog in my throat” means “to be unable to speak clearly because your throat feels dry or blocked”. Example: In the interview I got a frog in my throat and had to cough many times before I could answer the questions.
“Up to scratch” means “at an acceptable standard or quality”. Example: Claire went out last night instead of spending time working so I’m not surprised that her essay was not up to scratch. Origin: This idiom originates from early boxing matches when.
idiomland: “ “Give somebody a piece of your mind” means “to speak angrily to someone because they have done something wrong”. Example: I’m going to give that mechanic a piece of my mind if the car’s not fixed this time.