Verbs

(v)append, tag on, tack on, tack, hang onfix to; attach“append a charm to the necklace”
(v)persevere, persist, hang in, hang on, hold onbe persistent, refuse to stop“he persisted to call me every night”, “The child persisted and kept asking questions”
(v)hang on, hold the line, hold onhold the phone line open“Please hang on while I get your folder”