Why do the English put a "R" on random words?

[Reidy's Bottle Of Grecian]

if there's a bloke who knows about baiting, it's the master baiter

 

[Matt Damon]

if there's a bloke who knows about baiting, it's the master baiter

Theres plenty of those around it seems tonight.

 

[bluebloodinmyveins]

 

[Clint Planet]

Thats grammar. Not Phonetics.

"That's"

 

[chicoazul]

Theres plenty of those around it seems tonight.

puts hand up*

 

[Matt Damon]

"That's"

I told you, Its Phonetics not grammar.

 

[bluebloodinmyveins]

This explains everything. I totally get it now......

 

[Clint Planet]

I told you, Its Phonetics not grammar.

"It's"