Coming In Handy

( it was convenient to have that thing ... )

A thing which "comes in handy" is very useful to have. Example: "I'm glad you brought your knife." Reply: "Yes, it really comes in handy."

A thing or a skill which really helps you "comes in handy". Example: "Having your dog with us on this hunting trip really came in handy." Another example: "That is a great little tent. I bet it really comes in handy." Another example: "Speaking Spanish really comes in handy." Another example: "I carry a pen and paper at all times. They really come in handy."