It takes two AND It takes two to tango. Are both these expressions used? Is one of them more common?
The full expression is "It takes two to tango". However, the expression is so well-known and used that it is frequently shortened to "It takes two" and it is assumed that the listener will get the gist without the final two words.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
Unfortunately for ESL students, we commonly truncate common idioms, proverbs, clichés etc, expecting listeners to finish them for themselves.
A: 'So many people have given me their advice I just don't know what to do.'
B: 'That's your problem: too many cooks....'
A: 'I'll just have to wait and see what happens.'
B: 'That'll be best. Don't count your chickens....'
Doesn't this happen in other languages?