Catenation happens when a word ends in a consonant sound and the beginning of the next word starts with a vowel sound. In this situation, the consonant is moved to the ensuing vowel and pronounced like one word. These are examples:
this afternoon → thi safternoon
turn off → tur noff
this orange → thi (/s/)orange
that orange → tha t(/d/)orange
dropoff → dro poff
sleepearly → slee pearly
wake up → wa kup
not at all → no t(/d/)a t(/d/)all
still early → stil learly
get out of → ge t(/d/)ou t(/d/)of
weekend off → weeken doff
took off →too koff
come over → co mover
cats and dogs → cat san dogs