Pronunciation — Elision

"I don't know when they finished work yesterday."

ما معنى Elision؟ وأين يحدث في هذه الجملة؟

"My landlady bought a new handbag the other day."

أين يحدث Elision في كلمة landlady وhandbag؟

"I watch TV most evenings; in fact I watched it for five hours last night."

لماذا يختفي صوت t في fast وlast وwatched في الكلام السريع؟