The grammar of 'Ready to take' versus 'Easy to take'

Question

Why is this ungrammatical?:

1. * The medicine is easy to be taken.

when we can say:

2. The medicine is ready to be taken.

What is the difference between "ready" and "easy" that makes the one statement grammatical and the other ungrammatical?

Answer 1

1. *The medicine is easy [ to be taken ]. -- (ungrammatical)

2. The medicine is ready [ to be taken ].

SHORT ANSWER: The reason why the OP's example #1 is ungrammatical and example #2 is grammatical is because the adjective "easy" and the adjective "ready" are in two different subclasses of adjectives. That is:

• The subclass of adjectives that "easy" is a member of is one that doesn't allow the matrix subject to be linked to a subject gap in the infinitival. And that is why example #1 is ungrammatical.

• The subclass of adjectives that "ready" is a member of is one that happens to allow the matrix subject to be linked to a subject gap in the infinitival. And that is why example #2 is grammatical.

(Note: the matrix subject for the OP's two examples is "The medicine".)

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LONG VERSION:

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To see why example #1 is considered to be ungrammatical, we'll first look at a version that is both grammatical and means what the writer had most likely wanted that example #1 to mean:

• 3.a. The medicine is easy [ to take ].

In version #3.a, notice that the infinitival clause "to take" does not have an explicit subject, nor does it have an explicit object. The missing subject can be assumed to have the meaning of "anyone", and the missing object is understood to have the meaning of "the medicine". The below is what the infinitival "to take" clause would look like with explicit subject and object:

• [ for anyone to take the medicine ]

But if we try to plug that explicit version into #3.a, we'll get an ungrammatical result:

• 3.b. *The medicine is easy [ for anyone to take the medicine ]. -- (ungrammatical)

It can become grammatical if the explicit object of the infinitival "to take" is made covert:

• 3.c. The medicine is easy [ for anyone to take the medicine ].

Also, the subject of the infinitival "to take" is optional, and so, the parse version can be:

• 3.d. The medicine⁽ⁱ⁾ is easy [ (for anyone) to take ____⁽ⁱ⁾ ].

The parse version #3.d shows that there is a gap "____(i)" which represents a missing object for the transitive "take", and the meaning of that object can be recovered from the gap's antecedent which is the matrix subject "medicine", and that linkage between them is shown by the index "i".

So, in summary, the important point is that the adjective "easy" allows the matrix subject to be the antecedent for the object gap that is in the infinitival "to take" clause.

Now let's look at what's going on with the OP's #1 example to find out why it doesn't work:

• 1. *The medicine is easy [ to be taken ]. -- (ungrammatical)

When it is compared to the good version #3.a, you'll see that the difference is in the infinitival "to take / to be taken" clauses. The infinitival is an active voice clause in the good #3.a version, but is a passive voice clause in the bad #1 version.

If those two versions were to have the same meaning, then the passive infinitival in example #1 would have to be interpreted as:

• [ for the medicine to be taken (by anyone) ]

where the two arguments of the infinitival are switched (when the passive is compared to the active). Now let's look at the parse version of example #1:

• 1.d. The medicine⁽ⁱ⁾ is easy [ ____⁽ⁱ⁾ to be taken (by anyone) ].

Since version #1.d is not acceptable (i.e. not grammatical), then, we can assume that means that the adjective "easy" does not allow the subject gap of the infinitival to link to an antecedent that is a matrix subject.

POINT #A: It seems that the adjective "easy" only allows the matrix subject to be linked to a non-subject gap in the infinitival. That is, it doesn't allow the matrix subject to link to the infinitival's subject gap. And that is why the OP's example #1 is ungrammatical.

But the OP's example #2 is grammatical, so why does it work? It works because it uses a different adjective ("ready"), and that adjective is in a different subclass of adjectives from the one that "easy" is a member of. The parse for #2 is:

• 2.d. The medicine⁽ⁱ⁾ is ready [ ____⁽ⁱ⁾ to be taken (by anyone) ].

The subclass of adjectives that "ready" is a member of is one that happens to allow the matrix subject to be linked to a subject gap in the infinitival. And that is why the OP's example #2 is grammatical.

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VERIFICATION CHECK:

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Let's confirm the behavior of the adjective "easy". To do this, let's use an infinitival "to throw" and use it as a ditransitive verb, and so, there will be more opportunities for available gaps in the infinitival clause.

Let's see the declarative clause version that could correspond to the infinitival "to throw" ditransitive clause (and also see that infinitival ditransitive clause):

• [ Tom ] threw [ Sue ] [ the ball ]. -- (declarative clause)

• [ for Tom ] to throw [ Sue ] [ the ball ] -- (infinitival clause)

The infinitival has three arguments, which are associated with the three functions: subject, indirect object, direct object. Let's see which of those functions can be gapped and linked to the matrix subject for a ditransitive infinitival clause.

Active voice: The active voice versions of the infinitival clause:

• 4.1. *Tom⁽ⁱ⁾ is easy [ ____⁽ⁱ⁾ to throw [ Sue ] [ the ball ] ]. -- (ungrammatical)

• 4.2. *Sue⁽ⁱ⁾ is easy [ (for Tom) to throw ____⁽ⁱ⁾ [ the ball ] ]. -- (ungrammatical)

• 4.3. The ball⁽ⁱ⁾ is easy [ (for Tom) to throw [ Sue ] ____⁽ⁱ⁾ ]. -- (GOOD)

The only good version is #4.3 ("The ball is easy (for Tom) to throw"), which links the matrix subject to the infinitival's direct object gap. And also notice that the indirect object has to be omitted for it to be good.

This helps to confirm point #A. That is, that the adjective "easy" only allows the matrix subject to be linked to a non-subject gap in the infinitival -- which means that it doesn't allow the matrix subject to link to the infinitival's subject gap.

Passive voice: Now, let's use the passive voice version of the infinitival clause:

• 4.4.a *Tom⁽ⁱ⁾ is easy [ (for the ball) to be thrown [ Sue ] [ by ____⁽ⁱ⁾ ] ]. -- (ungrammatical)

• 4.4.b *Tom⁽ⁱ⁾ is easy [ (for Sue) to be thrown [ the ball ] [ by ____⁽ⁱ⁾ ] ]. -- (ungrammatical)

• 4.5.a *Sue⁽ⁱ⁾ is easy [ ____⁽ⁱ⁾ to be thrown [ the ball ] (by Tom) ]. -- (ungrammatical)

• 4.5.b *Sue⁽ⁱ⁾ is easy [ (for the ball) to be thrown ____⁽ⁱ⁾ (by Tom) ]. -- (ungrammatical)

• 4.6.a *The ball⁽ⁱ⁾ is easy [ ____⁽ⁱ⁾ to be thrown [ Sue ] (by Tom) ]. -- (ungrammatical)

• 4.6.b *The ball⁽ⁱ⁾ is easy [ (for Sue) to be thrown ____⁽ⁱ⁾ (by Tom) ]. -- (ungrammatical)

None of these versions seem to work. This neither helps to confirm or disprove point #A.

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Let's also do this for the corresponding mono-transitive infinitival clauses.

• [ Tom ] threw [ the ball ] [to Sue]. -- (declarative clause)

• [ for Tom ] to throw [ the ball ] [to Sue] -- (infinitival clause)

Active voice: The active voice versions of the infinitival clause:

• 5.1. *Tom⁽ⁱ⁾ is easy [ ____⁽ⁱ⁾ to throw [ the ball ] [ to Sue ] ]. -- (ungrammatical)

• 5.2. ? Sue⁽ⁱ⁾ is easy [ (for Tom) to throw [ the ball ] [ to ____⁽ⁱ⁾ ] ]. -- (doubtful)

• 5.3. The ball⁽ⁱ⁾ is easy [ (for Tom) to throw ____⁽ⁱ⁾ [ to Sue ] ]. -- (GOOD)

The only good version is #5.3 ("The ball is easy (for Tom) to throw"), which links the matrix subject to the infinitival's direct object gap. Though, version #5.2, which links the matrix subject to a preposition phrase's object gap might be acceptable.

This helps to confirm point #A. That is, that the adjective "easy" only allows the matrix subject to be linked to a non-subject gap in the infinitival -- which means that it doesn't allow the matrix subject to link to the infinitival's subject gap.

Passive voice: Now, let's use the passive voice version of the infinitival clause:

• 5.4.a *Tom⁽ⁱ⁾ is easy [ (for the ball) to be thrown [ to Sue ] [ by ____⁽ⁱ⁾ ] ]. -- (ungrammatical)

• 5.4.b *Tom⁽ⁱ⁾ is easy [ (for Sue) to be thrown [ the ball ] [ by ____⁽ⁱ⁾ ] ]. -- (ungrammatical)

• 5.5.a *Sue⁽ⁱ⁾ is easy [ ____⁽ⁱ⁾ to be thrown [ the ball ] (by Tom) ]. -- (ungrammatical)

• 5.5.b *Sue⁽ⁱ⁾ is easy [ (for the ball) to be thrown [ to ____⁽ⁱ⁾ ] (by Tom) ]. -- (ungrammatical)

• 5.6.a *The ball⁽ⁱ⁾ is easy [ ____⁽ⁱ⁾ to be thrown [ to Sue ] (by Tom) ]. -- (ungrammatical)

• 5.6.b *The ball⁽ⁱ⁾ is easy [ (for Sue) to be thrown ____⁽ⁱ⁾ (by Tom) ]. -- (ungrammatical)

None of these versions seem to work. This neither helps to confirm or disprove point #A.

CONCLUSION: This section seems to strongly help to confirm point #A. That is, that the adjective "easy" only allows the matrix subject to be linked to a non-subject gap in the infinitival -- which means that it doesn't allow the matrix subject to link to the infinitival's subject gap.

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REFERENCES:

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CGEL:

• "tough": pages 1246-7, 1247 fn 48.
• "easy": pages 1245-7, 1252-3.
• "ready": pages 1246-8, 1258.

Important sections:

• pages 1245-8
• page 1245 [2.ii] [2.iii-iv] -- "easy"
• page 1247 [7] [9]
• page 1257 [3] [4-6] -- When "ready" has an ordinary infinitival, it takes ordinary subject.

Note that CGEL is the 2002 reference grammar by Huddleston and Pullum et al., The Cambridge Grammar of the English Language.

Answer 2

Tough adjectives

1. The medicine is easy to take

If we want to understand how this sentence works, we need to know the parts of the sentence. They work like this (Predicator is the job that the verb does):

• The medicine [Subject]; is [Predicator]; easy to take [Complement]

The complement "easy to take" is an adjective phrase. It has an adjective easy as the head of the phrase. Easy is taking a to-infinitive, to take.

When we have an infinitive we need to understand what the subject of the infinitive is. If the infinitive verb takes an object, we need to understand what the object of the infinitive is too. When a to-infinitive is part of an adjective phrase, the grammar of the adjective usually tells us what the subject or object of the infinitive is.

The adjective easy is a TOUGH adjective. This means that it behaves like other Tough adjectives. When we have a Tough adjective, we understand the subject of the infinitive from the context. If it is not a specific person, then we usually understand the subject as 'people in general' or 'somebody'. We understand the subject of the infinitive in example 1 like this:

• The medicine is easy [for somebody to take].

However, the verb take usually has an object too. Tough adjectives have a special rule about the objects of infinitives. When a Tough adjective has an infinitive, the object of the infinitive is the same as the subject of the main verb in the sentence. In example (1), the subject is the medicine. We understand the sentence like this:

• The medicine_(i) is easy [ for somebody to take it_(i) ]

In other words, like this:

• The medicine is easy [ for somebody to take the medicine ]

We can see that the adjective easy needs the subject of the main verb to be the same as the object of the infinitive verb. Look what happens if the infinitive verb doesn't have an object:

• *The man is easy to smile. (wrong)

This sentence does not make sense. This is because the man cannot be the object of the verb smile. We cannot understand the sentence like this because it does not make sense:

• *The man is easy [for somebody to smile the man]. (wrong)

In the Original Poster's question there is no object of the infinitive, because the infinitive is passive. Passive verb forms of verbs like this do not have an object!:

• *The medicine is easy to be taken. (wrong)

We cannot try to understand the sentence like this:

• *The medicine is easy [for somebody to be taken the medicine]. (wrong)

Control adjectives

2. The elephant is keen to eat.

Keen is a CONTROL adjective. Control adjectives are different from Tough adjectives. When Control adjectives take to-infinitives, we understand that the subject of the infinitive is the same as the subject of the main verb. Example (2) means:

• The elephant is keen [ for the elephant to eat ]

The adjective READY

Ready can behave like a Tough adjective:

• The medicine is easy to take.
• The medicine is ready to take.

But ready can also behave like a Control adjective:

• The elephants are keen to eat.
• The elephants are ready to eat.

Because ready can behave like a Control adjective we can use it with a passive to-infinitive construction:

• The medicine is ready to be taken.

This means:

• The medicine_(i) is ready [ for it_(i) to be taken ].

This is why the Original Poster's ready example was grammatical, but the easy example wasn't.

It is possible to make some good jokes with the adjective ready, because sometimes it is not clear whether we are using it as a Tough adjective, or a Control adjective. For example, you need to be very careful if a cannibal says this to you:

• Are you ready to eat?

Because this might mean:

• Are you ready [ for somebody to eat you ]?

Hope this is helpful!

Answer 3

A person takes the medicine, and it's easy for the person to take it. So, take in the first sentence should be active:

The medicine is easy [for a person] to take.

The medicine doesn't take; it gets taken by a person. So, take in the second sentence is passive:

The medicine is ready to be taken [by a person].

On the other hand, take could also be active in this sentence and the meaning would be the same, only with a slight shift of emphasis (toward the act of taking it and away from the medicine itself):

The medicine is ready [for a person] to take.

But why?

Why does easy make a person the implied subject of to take and not allow a passive form like ready? Because it just does. If you want a deep, thorough explanation of what's going on, see Araucaria's answer. But if you're just learning English, all you have to do is remember easy to take as a stock phrase. Other adjectives with comparable meanings in similar phrases create similar expectations about the subject of the verb. For example, you can't make the verb passive in any of these (without changing something else in the sentence):

This steering wheel is hard to turn.

This theorem is trivial to prove.

Tonight, the Milky Way is impossible to see.

Miniature golf is fun to play.

These shoes are uncomfortable to wear.

Ice cream is yummy to eat.

Velvet is pleasant to feel.

That river is dangerous to cross.

The grammatical principle here is baffling to understand.

Do you see a common pattern? Sort of? A little bit? The pattern is hazy, you say? Excellent. This is how it is for native speakers, too. Actually, some people do use the passive forms of the verb in those, sometimes. What's really happening is that people are making new phrases by analogy with familiar phrases, just like you. The only difference is that fluent speakers have a much larger body of experience to determine what is a familiar phrase and what is unfamiliar. They can make a better educated guess about how other people will fill in the implied subject of the verb. Different native speakers make different educated guesses, though.

To smash any remaining hope you might have that there could be a clear and simple rule for this, here are some examples that allow both passive and active forms of the verb, with various differences:

A good writer is eager to be understood [by readers]. / A good reader is eager to understand [what is written].

The course on linguistics is too easy to be taken seriously. / The course on linguistics is too easy to take seriously. [Both have the same meaning.]

The door is likely to open. / The door is likely to be opened. [Almost the same meaning.]

The patient is able to see [with his/her eyes]. / The patient is able to be seen [by visitors at the hospital].

It's easy [for a crooked person] to take gullible people. / It's easy [for a gullible person] to be taken by crooks.

And look at this:

The medicine is easily taken.

The medicine is readily taken.

but not:

The medicine is easily to be taken.

The medicine is readily to be taken.

Answer 4

In the case of:

The medicine is easy to be taken?

easy is just describing a quality of the medicine. As such take would be better.

The medicine is easy to take?

But in the case of:

The medicine is ready to be taken?

is ready is a continuing state (such as not ready, ready, swallowed) that expects a future action (that you will take it). So "taken" is OK.