Adverbs of comment state a comment, or opinion about a situation.

Adverbs of comment among others are: actually, apparently, certainly, clearly, cleverly, confidentially, definitely, disappointingly, foolishly, fortunately honestly, happily, hopefully, ideally, kindly, luckily, naturally, obviously, possibly, presumably, seriously, simply, surely, surprisingly, thankfully, undoubtedly, unfortunately, wisely, etc.

Adverbs of comment are usually placed at the beginning of a sentence and are separated from the rest of the sentence by a comma.
Examples:
1. Definitely, I don’t agree with your plan.
2. Obviously, she refused to participate in that program.
3. Clearly, the teacher explained the subject.
4. Cleverly, he fixed my broken tablet.
5. Foolishly, the boy kicked the ball to his own goalpost.
Adverbs of comment also can be placed in mid-position, before the main verb but after be.

Examples:

1. We certainly enjoyed the concert.
2. He surprisingly came to my party last night.
3. The boy confidentially sang the song on the stage.
4. She is simply beautiful.
5. They are possibly honest.

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