总是 indicates either a regular action or a habit.
It is placed before the predicate.
Examples
妈妈总是晚上九点去睡觉
My mother always goes to bed at 9 p.m.
māma zǒngshì wǎnshàng jiǔ diǎn qù shuìjiào
上课的时候我总是很累
I'm always tired during lessons
shàngkè de shíhou wǒ zǒng shì hěn lèi
The adverb 总
You can also use 总 instead of 总是.
总 is used in the following cases:
1) with modal verbs. For example: 要 , 会 , 能 .
Examples
我的朋友总能找到价格便宜的航班
My friend always finds cheap flights
wǒ de péngyou zǒng néng zhǎodào jiàgé piányi de hángbān
2) in negation together with the negative adverbs 不 or 没 meaning "never".
Examples
他总不担心
He never worries
tā zǒng bù dānxīn
3) for expressing old habits.
Examples
以前我总早上八点起床
I always used to get up at 8 a.m.
yǐqián wǒ zǒng zǎoshang bā diǎn qǐchuáng
The adverb 老是
老是 expresses that an action or a condition constantly repeats or continues.
老是 is placed before the predicate. You can also use 老 instead of 老是.
Pay attention
It is usually used in the context of a complaint.
Examples
你老是笑话我!
You always laugh at me!
nǐ lǎoshì xiàohuà wǒ
小明老迟到上课
Xiao Ming is always late for class
xiǎomíng lǎo chídào shàngkè
The adverb 一向
The adverb 一向 is used to express a habit or attitude which has continued for a long period of time up to the present moment. When you use 一向, you're conveying a sense that "it's always been this way."
Pay attention
一向 cannot be used with verbs involving changes or actions. In this case, 一直 should be used. You can read more about 一直 below.
一向 cannot be used to express actions in the future. 一直 can be used instead.
Examples
妈妈一向支持我的决定
My mother has always supported my decisions (she still supports me)
māma yíxiàng zhīchí wǒ de juédìng
我一向不喜欢点外卖
I have never liked ordering takeout (I still don't like it)