to + inf. + something
I learn English to speak more fluently

so + obj./subj. pronoun + modal + clause
She trains hard so she can can win the race.

so that + obj./subj. pronoun + modal + clause
Carlos is on a diet so that he will lose weight.

so as + to + inf + clause
I finished work early so as to get home early.

so as not to + inf. + clause
I took an umbrella so as not to get wet in the rain.

to avoid + ing. + clause
I save money to avoid having money problems.

in order to + inf. + clause
She murders her husbands in order to inherit their money.

in order not to + inf. + clause
Clara doesn’t drink alcohol in order not to make a fool of herself at parties.

in case + subj. / obj. + clause
I am taking a coat in case it gets cold later.