First of all, when transmitting you are in PRESENT TENSE not PAST TENSE!
You don’t speak this way when talking on the phone or to someone face to face! eg.
Should be :
"ABC, Taxiing runway 18 for a departure to the South"
NOT
"ABC, Taxi's runway 18 for a departure to the South"
Aren't they both present tense? Notwithstanding the apostrophe which would make the second example mean "taxi is runway..." or the runway belongs to the taxi. I am on leave and am a pedantic controller!