那倒(也)是, 算了, 就是说: conversation moves
【六32】【六33】【六34】固定短语 / phrases
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
Three set phrases that are very frequent in speech, for reacting to what the other person says.
那倒(也)是 means "that's true": you grant a point you had not thought of (倒 always comes before 也). 算了 (or 算了吧) means "forget it, never mind": you drop a plan, an argument or a grievance (算了，不说了). 就是说 or 这就是说 means "in other words, that means": you rephrase or draw the consequence (这就是说，责任不在你).
Shades: 算了 gives up, whereas X就X吧 (previous point) accepts and carries on; 就是说 is lighter than 换句话说 (level 5). It never means "it is said that": for hearsay, use 据说. All three belong to everyday speech.
Examples
算了，不等了，我们先走吧。
Suàn le, bù děng le, wǒmen xiān zǒu ba.Forget it, let's not wait any longer: let's go.
“路上堵车，坐地铁更快。”“那倒也是，我怎么没想到呢！”
“Lùshang dǔchē, zuò dìtiě gèng kuài.” “Nà dào yě shì, wǒ zěnme méi xiǎngdào ne!”"The road's jammed; the metro would be quicker." "True, why didn't I think of that!"
为了这点小事吵架，算了吧。
Wèile zhè diǎn xiǎoshì chǎojià, suàn le ba.Arguing over a little thing like this? Let it go.
这就是说，下个月房租要涨了。
Zhè jiù shì shuō, xià ge yuè fángzū yào zhǎng le.That means the rent goes up next month.
他三天没回消息，电话也不接，这就是说，他根本不想见我们。
Tā sān tiān méi huí xiāoxi, diànhuà yě bù jiē, zhè jiù shì shuō, tā gēnběn bù xiǎng jiàn wǒmen.He hasn't replied in three days and won't pick up, which means he doesn't want to see us at all.
你的意思就是说，这次旅行取消了？
Nǐ de yìsi jiù shì shuō, zhè cì lǚxíng qǔxiāo le?So what you mean is that the trip is off?
Common mistakes
✗ 那也倒是 → ✓ 那倒也是 (倒 comes before 也).
✗ 就是说他搬家了。 → ✓ 据说他搬家了。 (就是说 means "in other words", never "it is said that").