'Search for my tongue' The poet feels she has lost an important part of herself that she needs to recover to feel herself again.
'lost the first one, the mother tongue, and could not really know the other' The original language is associated with being nurturing, protecting, loving. The second language is seen to be alien. The poet feels it is not possible to fully understand or become completely part of another culture.
'if you lived in a place you had to/speak a foreign tongue' There is a suggestion that some people would not be allowed to speak their own language, that a foreign language has been imposed.
'You had to spit it out' 'The choice of words makes the original language sound like something disgusting, like phlegm perhaps. This may suggest the way the original language was seen by the foreigners as something inferior to their own language.'
'it ties the other tongue in knots' The two languages are imagined as being in battle, with the invader being defeated. Clearly this can be seen to refer to colonial powers and independence.
'Every time I think I've forgotten it blossoms out of my mouth' The first language/culture is shown to be lasting, and in the flower imagery is thought of here as something natural, beautiful and eternal.
The language of the poem is ordinary and conversational 'You ask me','I ask you' - until line