I wonder why.
I wonder what happened.
I wonder if this is love.
I wonder why he did that.
I wonder what he will say.
I wonder what happened to her.
I wonder why she is so worried.
I wonder who started that rumor.
I wonder if they'll get divorced.
I wonder if it will rain tomorrow.
I wonder if the weather will hold.
I wonder why she didn't tell him about it.
I wonder why John is always late for school.
I wonder if she'll recognize me after all these years.
Some dog owners wonder if it's OK to feed their dogs fish.
Some dog owners wonder if they are feeding their dogs enough.
I haven't heard anything from him since then. I wonder what in the world he's doing.