1. Explain it simply
往往 (wǎngwǎng) means 'tend to' or 'more often than not'. It reports a regular tendency, not a single event.
Word order: Subject + 往往 + verb / adjective, as in 他往往很晚才睡觉 (he tends to sleep late).
Because it describes a pattern, 往往 usually pairs with a condition or repeated situation, not a one-time future plan.
Keep 往往 before the predicate - it cannot sit at the end of the sentence.
2. Show examples
他往往很晚才睡觉。
Tā wǎngwǎng hěn wǎn cái shuìjiào.
He tends to go to bed very late.
往往 sits before 很晚才睡觉
周末的时候，这条街往往很热闹。
Zhōumò de shíhou, zhè tiáo jiē wǎngwǎng hěn rènao.
On weekends, this street tends to be very lively.
a regular weekend pattern
便宜的东西往往质量不好。
Piányi de dōngxi wǎngwǎng zhìliàng bù hǎo.
Cheap things tend to be poor in quality.
a general tendency, not one case
3. Share a tip
Use 往往 for tendencies, not single plans - say 他往往很晚睡觉, not a one-time 明天他往往很晚睡觉.