Start to wonder vs Begin to wonder (Which one is correct?)
I would like to know which of these forms ("to start to wonder", "to begin to wonder") is the correct one to use or the most common.

Examples:
1. I am STARTING TO WONDER what all my Facebook friends and Twitter followers have been doing this week.
2. I am BEGINNING TO WONDER what all my Facebook friends and Twitter followers have been doing this week.

Question

Start to wonder vs Begin to wonder (Which one is correct?)
I would like to know which of these forms ("to start to wonder", "to begin to wonder") is the correct one to use or the most common.

Examples:
1. I am STARTING TO WONDER what all my Facebook friends and Twitter followers have been doing this week.
2. I am BEGINNING TO WONDER what all my Facebook friends and Twitter followers have been doing this week.

Answer

Both are correct! It's up to you to choose whichever one you prefer using. "Starting" to wonder is the most commonly used one, but "beginning" to wonder is just as correct.

Answer

They are very much interchangeable, but I think 'starting' is more common in normal conversation.