switch between languages(Researchers have uncovered what’s happening in the brain when we switch between different languages. The finding provides new insights into the nature of bilingualism.futurity.orgShabe)
phase in(phase (something) in or phase in (something) : to start to use or do (something) gradually over a period of time : to introduce (something) slowly The country is phasing in new paper currency. The tax cut will be phased in over the next three years. The law will phase tax cuts in over a period of two years. MWALD Alexander Demidov)
