This lesson explains the differences between these two sentences:

1. John is so tall.
2. John is too tall.

Let's begin with #1 - the rules for so.

John is so tall.

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So is used before an adjective for emphasis (to make the statement stronger). Let's compare these sentences:

so + adjective

• The soup is hot.
• The soup is so hot.

The second sentence is stronger. Here, so has a similar meaning to 'very' (but it is a little stronger). The same is true of sentences with 'so many/much' + a noun. For example:

so many/much + noun

• He has many friends.
• He has so many friends.

So in the second sentence is an intensifier and is used for emphasis, making the sentence a little bit stronger. When so many or so much are used before a noun, it means a lot. If you have a lot of money, then you have so much money.

(Remember: many is used before plural countable nouns (e.g. friends, people); much is used before uncountable nouns (e.g. money, wine).)

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Note: So cannot be used before a noun. For example, we cannot say 'He is so nice man'. Instead, we use such (He is such a nice man). For a review of this grammar, please visit this page on the difference between so and such.

 

John is too tall.

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Too is used for emphasis also, but it means 'more than needed' or 'more than enough.' It is used to show that something is bad (negative) or that something is over the desired limit. Take a look at these ideas:

1. John is so tall. He plays basketball well. (His tallness is not a bad thing)
2. John is too tall. He cannot sit comfortably on an airplane. (His tallness is a bad thing)

The second sentence means that he is very tall and that is a bad thing. His height is over the limit. He is 2 meters tall. Therefore he cannot fit on an airplane. John is too tall.

Let's look at more examples.

1. You work so hard. I wish everyone worked like you. :)
2. You work too hard. You should take a break. :(

Again, the second sentence is a negative comment. You are saying that the person works more than enough and should work less.

Because too describes something bad (negative), the below sentences do not make sense.

• • This is too delicious! = This is so delicious.
  • I am too happy! = I am so happy
  • She is too beautiful! = She is so beautiful.

These sentences all describe good (positive) things, so we do not use too.

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Note: Too is often used in the structure too + adjective/adverb + infinitive

• The pizza is too hot to eat. = (The pizza is too hot. I cannot eat it)
• You are too young to watch that movie. = (You are not old enough)
• I was too tired to do my homework. ( = I didn't do it. My tiredness was 'over the limit', so I slept).
• She ran too slowly to win the race. (= Her speed was too slow; she could not win)
• She speaks too poorly to get a job. (= Her writing is not good enough; she cannot get a job)

Again, in all these sentences, too means over the limit or more than a desired quantity/level. 

Thanks to englishcurrent.com