What is classical conditioning and language acquisition ?

Classical conditioning was developed by Ivan Pavlov (1849-1936). He did an experiment with dogs. He kept two stimuli: conditioned (a bell) and unconditioned (food). He offered food to the experimental dogs,  and he saw saliva (water in mouth)  in the dogs ' mouths. However,  when he only rang the bell,  there was no saliva in the dogs' mouths. Then,  when he rang the bell and gave them food,  the dogs salivated again. Finally,  he rang the bell and did not give food; but,  there was saliva in the dogs' mouths. This salivation is called a conditioned response. The dogs became naturally conditioned to salivate at the ringing of the bells. This process is called classical conditioning. 

Language acquisition can be explained through this classical conditioning. Learners can respond differently to some words based on their previous experience related to those words. If learners are exposed to the same expressions repeatedly in a systematic way,  they will learn those expressions easily. This helps students learn various language mechanics through frequent reinforcement. It may also influence learners in developing certain behavior to develop proficiency in language use through reinforcement.