The basic idea: look at what follows the intensifier
So and such often express a high degree of a quality, creating emphatic descriptions or reactions. The choice depends on the English structure that follows, not on how the sentence translates into another language.
Use so before an adjective or adverb without a following noun. Use such before a noun or a whole noun phrase.
A useful question while speaking is: after the intensifier, am I naming a quality or a manner of action, or a thing, person, event, or substance?
so + adjective or adverb | such + noun phrase
- NP / noun phrase —
- A noun phrase: a noun with its dependent words, such as the new student; the pattern treats it as one group of words.
- noun —
- A word naming a person, thing or idea: student, book, happiness.
- adjective —
- A word describing what someone or something is like: happy, tired, interesting.
- adverb —
- A word adding information about an action, quality or circumstance: slowly, very, often.
The room was so quiet.
The room was so quiet.
So is followed by the adjective quiet; there is no noun after the intensifier.
It was such a quiet room.
It was such a quiet room.
Such introduces the noun phrase a quiet room.
She answered so calmly.
She answered so calmly.
Calmly is an adverb describing the manner of answered, so use so.
So before an adjective or adverb
Place so directly before an adjective: so tired, so useful, so cold. A noun may appear elsewhere in the sentence, but it is not part of the phrase after so: The soup is so hot.
So also comes before an adverb: so slowly, so clearly, so carefully. Here it intensifies the manner of an action rather than a thing.
After be, look, feel, seem, and similar verbs, an adjective describes the subject, so the pattern remains so + adjective.
subject + be/look/feel + so + adjective | verb + so + adverb
- subject / S —
- The grammatical subject: who or what the clause is about; the verb agrees with it. In The book was written, the book is the subject, although someone else does the action.
- verb / V —
- A word for an action or state, such as work or be. The pattern determines its form.
- adjective —
- A word describing what someone or something is like: happy, tired, interesting.
- adverb —
- A word adding information about an action, quality or circumstance: slowly, very, often.
The soup is so hot.
The soup is so hot.
Hot is an adjective after is; so intensifies the quality itself.
The guide spoke so clearly.
The guide spoke so clearly.
Clearly is an adverb describing how the guide spoke.
You look so happy today.
You look so happy today.
Happy is an adjective after look; the English pattern is so + adjective.
Such with a singular countable noun
If such introduces one countable thing or person, use a or an: such a good idea, such an interesting book. The article follows such rather than preceding it.
The adjective is optional: such a mess and such a surprise are also correct. The noun, however, must remain part of the phrase.
Choose a or an according to the sound at the beginning of the next word: such a useful tool, but such an unusual tool.
such + a/an + (adjective) + singular countable noun
- noun —
- A word naming a person, thing or idea: student, book, happiness.
- adjective —
- A word describing what someone or something is like: happy, tired, interesting.
It was such a useful lesson.
It was such a useful lesson.
Lesson is a singular countable noun, so a is needed after such.
That was such an unusual question.
That was such an unusual question.
Use an before unusual; the whole phrase such an unusual question contains a noun.
The kitchen was such a mess.
The kitchen was such a mess.
Such can precede a + noun without an adjective.
Such with plural and uncountable nouns
Do not use a/an before a plural noun: such friendly people, such long meetings, such useful books.
Do not use a/an before an uncountable noun either: such bad weather, such useful information, such good advice. Remember that information and advice are uncountable in English.
The presence of a noun therefore points towards such, but the article depends on the type of noun.
such + (adjective) + plural noun | such + (adjective) + uncountable noun
- noun —
- A word naming a person, thing or idea: student, book, happiness.
- adjective —
- A word describing what someone or something is like: happy, tired, interesting.
They are such helpful neighbours.
They are such helpful neighbours.
Neighbours is plural, so the pattern is such + adjective + plural noun, without an article.
We had such bad weather.
We had such bad weather.
Weather is uncountable, so a/an is not used.
She gave me such useful advice.
She gave me such useful advice.
Advice is grammatically uncountable in English, even when it refers to more than one recommendation.
Two forms with similar meanings
The same reaction can often be expressed in two grammatical ways. The exam was so difficult describes a quality of exam; It was such a difficult exam names a whole noun phrase.
Both versions can be correct if their internal structure is correct. In an exercise requiring a specific pattern, another grammatical pattern may be outside the target, but that does not make it ungrammatical.
When rephrasing, check whether a noun has been added or removed and whether an article is required.
noun + be + so + adjective ↔ it + be + such + a/an + adjective + noun
- noun —
- A word naming a person, thing or idea: student, book, happiness.
- adjective —
- A word describing what someone or something is like: happy, tired, interesting.
The film was so funny. It was such a funny comedy.
The film was so funny. It was such a funny comedy.
The first sentence intensifies an adjective; the second intensifies a noun phrase. Both are correct.
The streets were so busy. They were such busy streets.
The streets were so busy. They were such busy streets.
In the second sentence, streets is plural, so there is no a/an after such.
The task was so easy. It was such an easy task.
The task was so easy. It was such an easy task.
Use an before easy task because the phrase begins with a vowel sound.
A result clause with that
Both patterns can be followed by a that-clause expressing a result: so cold that ... or such a cold day that .... The structure following the intensifier still determines the choice between so and such.
In spoken English, that is sometimes omitted, but the full pattern in this lesson helps make the cause-and-result relationship clear.
Not every sentence with so or such needs a result. A that-clause is needed only when the speaker actually states a consequence.
so + adjective or adverb + that + result | such + noun phrase + that + result
- NP / noun phrase —
- A noun phrase: a noun with its dependent words, such as the new student; the pattern treats it as one group of words.
- noun —
- A word naming a person, thing or idea: student, book, happiness.
- adjective —
- A word describing what someone or something is like: happy, tired, interesting.
- adverb —
- A word adding information about an action, quality or circumstance: slowly, very, often.
The box was so heavy that I asked for help.
The box was so heavy that I asked for help.
So intensifies heavy, and the that-clause states the result.
It was such a long queue that we left.
It was such a long queue that we left.
Such introduces a long queue, followed by the consequence.
She explained it so clearly that I understood at once.
She explained it so clearly that I understood at once.
So intensifies the adverb clearly, not a noun.
An important exception: so much, so many, so little, so few
Use so before much, many, little, and few when they express quantity: so much noise, so many people, so little time, so few buses. This is an important exception to the quick guideline “use such before a noun”.
Such as for giving examples, so as a conjunction meaning therefore, and formal patterns such as so difficult a task are outside this rule's target. Grammatical constructions outside the target should not be called errors.
A reliable A2 approach is to check for much/many/little/few first. Then choose so before an adjective or adverb and such before an ordinary noun phrase.
so + much/many/little/few + noun
- noun —
- A word naming a person, thing or idea: student, book, happiness.
There were so many people at the station.
There were so many people at the station.
Many specifies the number of countable people, so use so even though a noun follows.
We had so little time.
We had so little time.
Little specifies a small amount of uncountable time; the pattern uses so.
They gave us such useful information.
They gave us such useful information.
There is no much/little here. The ordinary noun phrase useful information requires such.
Common mistakes
Incorrect:It was such cold outside.
Correct:It was so cold outside.
Cold is an adjective without a following noun here, so use so before it.
Incorrect:It was so a long meeting.
Correct:It was such a long meeting.
A long meeting is a noun phrase. Such intensifies it, and the article follows such.
Incorrect:They are such friendly.
Correct:They are so friendly.
Friendly after are is an adjective without a stated noun following it.
Incorrect:She spoke such quietly.
Correct:She spoke so quietly.
Quietly is an adverb describing the manner of speaking; use so before an adverb.
Incorrect:We had such a bad weather.
Correct:We had such bad weather.
Weather is uncountable, so the article a cannot be used after such here.
Incorrect:There were such many people in the hall.
Correct:There were so many people in the hall.
Use so before many when it expresses quantity.