Questions & Answers about tā huì xiūchē, yě huì huàn liàntiáo.
Here 会 means can / knows how to / is able to because of learned skill.
So 他会修车 means he knows how to repair cars or he can repair cars.
In Mandarin, 会 can have different meanings depending on context:
- 会 + verb = know how to, be able to
- sometimes 会 can also mean will in the sense of future possibility
In this sentence, because it is followed by skills like 修车 and 换链条, it clearly means has the skill to do something.
It is used twice because the sentence mentions two separate abilities:
- 会修车 = can repair cars
- 也会换链条 = also can replace chains
Repeating 会 makes both abilities clear and balanced. This is very natural in Chinese.
You could think of the structure as:
- He can repair cars
- and he can also replace chains
Chinese often repeats helping words like this when listing abilities or actions.