To as a preposition or infinitive

[rojas0717]

What is the difference between an infinitive and a preposition phrase? The example: "Shannon sat on the front porch to finish her book report." Why is "to finish" considered an infinitive and not a prepositional phrase? Isn't "to" a preposition? I'm so thoroughly confused

I have read grammar texts but it is not clear to me
What about this sentences?

To improve my English, I need to practise more.
In spanish we use a preposition "para" + the infinitive form of the verb
Isn´t "to" a preposition in this sentence?

 

[MikeNewYork]

In both of your sentences, "to" is an infinitive marker, not a preposition. Nouns follow prepositions.

 

[TheParser]

I'm so thoroughly confused

***** NOT A TEACHER *****


Hello, Rojas:

I agree with you: the difference can be very confusing.

Here is a little trick that may help you a little bit.

Native speakers often use the words "in order" in front of an infinitive. Thus:

1. Shannon sat on the front porch in order to finish her book report.
2. In order to improve my English, I need to practice more.

When the word "to" is a preposition, the words "in order" would not be appropriate. Although you are still a learner, I am sure that you also find these sentences incorrect:

3. I went in order to the store.
4. Santa Claus gives gifts only in order to good children.
5. In order to my surprise, Mona said that she would marry me.

As you will agree, in #3 - 5 we may not use "in order," and so we have to call "to" a preposition.


P.S. I certainly do not speak Spanish, but I think that the words "in order to" mean something like "para" in Spanish.