Yabla Chinese

Yabla video uses of 叠加
怎么 zěnme
叠加 diéjiā
上 shàng
以后 yǐhòu
我 wǒ
就 jiù
不 bù
认识 rènshi
了 le
呢 ne
but how come when they are combined together, I can't recognize them anymore?