When we use the phrases so as to, in order to, and so that, we simply mean with the aim or purpose of doing something. The first two phrases are always followed by an infinitive to.
Will I not be altering the meaning of the sentence, if I put both phrases in order to/so as to in one sentence, and also the phrase so that separately in another sentence? As in:
We took off our shoes so as to/in order to avoid scratching the newly finished floors.
We took off our shoes so that we can avoid scratching the newly finished floors.
Explicitly asking, which one of these phrases are informal and which one, not?
And is it okay to simply put the to-infinitive in written exams?
- We took off our shoes to avoid scratching the newly finished floors.