“Zo” and “ze” are sentence suffixes that men often use with close friends, as in “iku zo” (let’s go) or “ame daze” (it’s raining). Young women acting manly sometimes use them. “Zo” is used as follows: When you blame someone, as in “omae, osoi zo” (You are late) or “zurui zo” (That’s not fair). When informing someone of your decision, as in “saa, iku zo” (Right, let’s go) or “issho ni yaru zo” (We’ll do it together). When you talking about your opinions or when thinking out to yourself, as in “kore ha mazui zo” (This is bad) or “nantoka dekiru zo” (I’ll be able to do it somehow). It is often used after “da,” as in “kimi no dazo” (This is yours) or “dekisou dazo” (It looks like I can make it). Sometimes it is added after “ja” as in “kore ja zo,” but this sounds like the sort of thing an old man might say. “Ze” is used as follows: When emphasizing something in an offhand manner, as in “omae ni makaseta ze” (I’ll leave it to you) or “aitsu kaetta ze” (He has gone home). When ordering others to do same thing as you, as in “yaru ze” (We’ll do it) or “iku ze” (We’ll go). In addition, it is also used when you arrogantly insist on something, as in “shitte ru ze” (I know it) or “dekiru ze” (I can do it). It is added after “da,” as in “kore daze” (This is it) or “aitsu daze” (It’s him), but not added after “ja.” Both “zo” and “ze” can also be added after the polite form “desu” or “masu.” But this antiquated expression is not usually used. These expressions are often used in period dramas.