This is the most common and general way of giving an opinion. You can use it both informally and formally: I think if you offer a consistently good service to your clients, they will keep coming back to you.
This is a more informal way of giving your opinion: I reckon it will be much faster to get to London by train.
These expressions are more formal and are often used when talking about important issues:
When you’ve thought about a situation carefully you could use either of these two expressions:
This is used when your opinion is critical. Sometimes, people say this even when their opinion hasn’t been asked for! – “If you ask me,…..” “But I didn’t ask you….!”
You would use this expression to give your opinion in a more familiar and forthright way.