Wild goose chase( পন্ডশ্রম ) Do not waste time in wild goose chase.
Come off with flying colours( জয়লাভ করা ) Our School team came off with flying colours.
By the by( প্রসঙ্গক্রমে ) By the by I came to know that he was ill.
From hand to mouth( দিন আনে দিন খায় ) The poor man lives form hand to mouth.
A blessing in disguise( বিপরীতে হিত ; প্রথমে খারাপ হিসেবে মনে হলেও পরবর্তীতে ভালো হয় ) Sam's motorcycle accident was a blessing in disguise because he got enough insurance money.
As if( যেন ) He swims so beautifully as if he is the Olympic gold medalist.