could
could \k*d, (')ku.d\ [ME couthe, coude, fr. OE cu-the; akin to OHG
konda]could past of CAN : - used in auxiliary function in the past {he
found he ~ go} <(he said he would go if he ~} : and as an alternative to
can suggesting less force or certainty or as a polite form in the present
{~ you do this for me} {if you ~ come we would be pleased}
Webster's English Dictionary