What is the grammar pattern in "藏语呢我是略知一二"？
It is a [topic + comment] sentence
Topic: '藏语呢' -- 'about the Tibetan language'
Comment: '我是略知一二(的)' -- 'I am slightly familiar with'
我是略知一二(的) is a relative phrase that gives a description/ comment on the topic/ object 藏语
SVO: '我對藏语略知一二' -- ''I am slightly familiar with the Tibetan language'
More example:

SVO: 我是不会再去这间餐厅的


T/P: 这间餐厅 我是不会再去的

in &quot;我 是 (XXX) 的&quot;, (XXX) describes &quot;我&quot;

SVO: 我不会再去这间餐厅了


T/P: 这间餐厅 我不会再去了

&quot;了&quot; is a final particle