"In order to" is a preposition that has an infinitive as its object. "In order that", by contrast, is a subordinating conjunction.
Both constructions, "in order to" and "in order that", are used to express purpose.
You should make a good impression in order to succeed in an interview.
We need to define a new strategy in order that the company could compete effectively.
The main differences between "in order to" and "in order that" are:
- Part of the speech. "In order to" is a preposition that has an infinitive as its object. "In order that" is a subordinating conjunction, and therefore it's always followed by a subordinate clause.
- Structure. While "in order to" is always followed by an infinitive (e.g., achieve, have, etc.), "in order that" is followed by a clause, that is, a subject and a verb (e.g., "in order that James can achieve...", "in order that I might have...", etc.)
- Formality. "In order that" is much more formal than "in order to". In fact, we use "in order that" in very formal or academic writing. "In order to" can be used in a wider range of contexts, including formal and neutral situations.
- Frequency. "In order to" is much more common than "in order that".
- Synonyms of "in order to". You can use just "to" instead of "in order to". Both constructions are possible in spoken and written English. Alternatively, in more formal environments, "in order to" and "so as to" are interchangeable.
- Synonyms of "in order that". "In order that" and "so that" are both subordinating conjunctions that have the same meaning and are used in the same way. In colloquial or everyday English, you can omit "that" from the "so that" construction and say simply "so".
If the following word is an infinitive, use "in order to" or just "to". In formal or academic writing, you can sporadically use "so as to" instead.
You need to fill out the form in order to get a passport.
When followed by a subject and a verb, use "in order that" or "so that". You can use just "so" in informal situations.
Fill out the form in order that you can get a passport.