two

no two ways about it used to convey that there can be no doubt about something.

put two and two together draw an obvious conclusion from what is known or evident.

☞ An extension of this phrase is put two and two together and make five, meaning 'draw a plausible but incorrect conclusion from what is known or evident'.

that makes two of us you are in the same position or hold the same opinion as the previous speaker.

two can play at that game used to assert that one person's bad behaviour can be copied to that person's disadvantage.

☞ For other idioms containing two, see the entry for the main word in the idiom (for example, for two pins at pin).