The relative adverbs where, when & why can be used to join sentences or clauses. They replace the more formal structure of preposition + which used to introduce a relative clause.

Formal structure, preposition + which	More common stucture using a relative adverb
That's the restaurant in which we met for the first time.	That's the restaurant where we met for the first time.
That picture was taken in the park at which I used to play.	That picture was taken in the park where I used to play.
I remember the day on which we first met.	I remember the day when we first met.
There was a very hot summer the year in which he was born.	There was a very hot summer the year when he was born.
Tell me the reason for which you came home late.	Tell me (the reason) why you came home late.
Do you want to know the reason for which he is angry with Sally?	Do you want to know (the reason) why he is angry with Sally?

Viewpoint and commenting adverbs

 

There are some adverbs and adverbial expressions which tell us about the speaker's viewpoint or opinion about an action, or make some comment on the action. These adverbs are different from other adverbs because they do not tell us how an action occurred. Commenting and viewpoint adverbs modify entire clauses rather than single verbs, adverbs, or adjectives. There is no real distinction between commenting adverbs and viewpoint adverbs, except in their sentence placement. Many adverbs that can be used as viewpoint adverbs can also be used as commenting adverbs. However, in some cases, an adverb is far more common as one or the other.

Sentence placement

Viewpoint adverbs are placed at the beginning, or more rarely, at the end of the sentence. They are usually separated from the rest of the sentence by a comma. Commenting adverbs are placed before the main verb unless the verb "to be" is used, in which case placement can be either before or after the verb. In some cases, commenting adverbs placed before the main verb will also be separated from the rest of the sentence by commas, although in most cases they will not be. In the examples below, viewpoint and commenting adverbs are shown in the correct sentence placements. When a sentence placement is unusual, stilted, or too formal for spoken language, it is marked with an asterisk.

Viewpoint or commenting adverb	At the start of a sentence	Before the main verb	At the end of a sentence
clearly	Clearly, he doesn't know what he is doing.	He clearly doesn't know what he is doing.	He doesn't know what he is doing, clearly.
obviously	Obviously, you are acting silly.	You are obviously acting silly	You are acting silly, obviously.
personally	Personally, I'd rather go by train.	I'd personally rather go by train.	I'd rather go by train, personally.
presumably	Presumably, he didn't have time to go to the post office.	He presumably didn't have time to go to the post office.	He didn't have time to go to the post office, presumably.
seriously	Seriously, I can't give this speech.	I seriously can't give this speech.	I can't give this speech, seriously.
surely	Surely you tried to get here on time.	You surely tried to get here on time.	You tried to get here on time, surely.
technically	Technically, we cannot fly to Mars and back.	We technically cannot fly to Mars and back.	We cannot fly to Mars and back, technically.
undoubtedly	Undoubtedly, he has a good reason not to come.	He undoubtedly has a good reason not to come.	He has a good reason not to come, undoubtedly.
bravely	Bravely, I kept on walking.	I bravely kept on walking.	*I kept on walking, bravely.
carelessly	Carelessly, she threw her book into the pond.	She carelessly threw her book into the pond.	*She threw her book into the pond, carelessly.
certainly	Certainly you should be there.	You certainly should be there. / You should certainly be there.	You should be there, certainly.
cleverly	Cleverly, Sally hid the jellybeans.	Sally cleverly hid the jellybeans.	*Sally hid the jellybeans, cleverly.
definitely	*Definitely, you are smart.	You defintely are smart. / You are definitely smart.	*You are smart, definitely.
foolishly	Foolishly, they cried out.	They foolishly cried out.	They cried out, foolishly.
generously	Generously, he donated the money.	He generously donated the money.	*He donated the money, generously.
stupidly	Stupidly, they played in the street.	They stupidly played in the street.	*They played in the street, stupidly.
obviously	Obviously, we are lost.	We are obviously lost. / *We obviously are lost.	We are lost, obviously.
kindly	Kindly, she fed the cat first.	She kindly fed the cat first.	She fed the cat first, kindly.
luckily	Luckily, you got here on time.	You luckily got here on time.	You got here on time, luckily.
fortunately	Fortunately, we found the boat.	We fortunately found the boat.	We found the boat, fortunately.
naturally	Naturally, you cannot be in the circus now.	You naturally cannot be in the circus now.	You cannot be in the circus now, naturally.
wisely	Wisely, she stayed home to take a nap.	She wisely stayed home to take a nap.	She stayed home to take a nap, wisely.
confidentially	Confidentially, I never gave him the envelope.		I never gave him the envelope, confidentially.
theoretically	Theoretically, we could send astronauts to Mars.	We could theoretically send astronauts to Mars. / We theoretically could send astronauts to Mars.	We could send astronauts to Mars, theoretically.
truthfully	Truthfully, I don't like chocolate much.	I truthfully don't like chocolate much.	I don't like chocolate much, truthfully.
disappointingly	Disappointingly, she got fourth place.	She disappointingly got fourth place.	She got fourth place, disappointingly.
thoughtfully	Thoughtfully, I turned away.	I thoughtfully turned away.	I turned away, thoughtfully.
simply	*Simply, I don't want to come.	I simply don't want to come.
unbelievably	Unbelievably, she showed up late again.	She unbelievably showed up late again.	She showed up late again, unbelievably.
unfortunately	Unfortunately, there is no more room.	There is unfortunately no more room. / There unfortunately is no more room.	There is no more room, unfortunately.

 

Adverbs of manner tell us how something happens. They are usually placed either after the main verb or after the object.
An adverb of manner cannot be put between a verb and its direct object. The adverb must be placed either before the verb or at the end of the clause.
If there is a preposition before the verb's object, you can place the adverb of manner either before the preposition or after the object.
Adverbs of manner should always come immediately after verbs which have no object (intransitive verbs).
These common adverbs of manner are almost always placed directly after the verb: well, badly, hard, & fast
The position of the adverb is important when there is more than one verb in a sentence. If the adverb is placed before or after the main verb, it modifies only that verb. If the adverb is placed after a clause, then it modifies the whole action described by the clause. Notice the difference in meaning between the following sentences.

Example	Meaning
She quickly agreed to re-type the letter.	the agreement is quick
She agreed quickly to re-type the letter.	the agreement is quick
She agreed to re-type the letter quickly.	the re-typing is quick
He quietly asked me to leave the house.	the request is quiet
He asked me quietly to leave the house.	the request is quiet
He asked me to leave the house quietly.	the leaving is quiet

Literary usage

Sometimes an adverb of manner is placed before a verb + object to add emphasis.
Some writers put an adverb of manner at the beginning of the sentence to catch our attention and make us curious.