I want some water to drink.

[angliholic]

I want some water to drink (it).
I want to drink some water (it).



Based on the second sample, it seems that "it" is justifiable to be inserted in the first sample. But in truth, it is not. So, why not? Thanks.

[Naamplao]

I want some water to drink (it).
I want to drink some water (it).



Based on the second sample, it seems that "it" is justifiable to be inserted in the first sample. But in truth, it is not. So, why not? Thanks.

The "it" does not belong in either sentence (in reality or implied).

In the first sentence

I want some water to drink

"to drink" is an infinitive acting as an adjective modifying "water". It is telling us what kind of water you wish. You want drinkable water, not water suitable for cleaning floors for example.

In the second sentence

I want to drink some water

"to drink some water" is an infinitive acting as a noun phrase which is the object of the verb "want". "Some water" is the object in the infinitive noun phrase "to drink some water".

"it" is not required or grammatically correct as you have proposed.

[angliholic]

Marvellously put! Naaplao. And thanks.

[RonBee]

The "it" does not belong in either sentence (in reality or implied).

In the first sentence

I want some water to drink

"to drink" is an infinitive acting as an adjective modifying "water". It is telling us what kind of water you wish. You want drinkable water, not water suitable for cleaning floors for example.

In the second sentence

I want to drink some water

"to drink some water" is an infinitive acting as a noun phrase which is the object of the verb "want". "Some water" is the object in the infinitive noun phrase "to drink some water".

"it" is not required or grammatically correct as you have proposed.