Linguistic- A big linguistic barrier is the grammar and composition of the learner's first language. As we learn to speak, we are taught certain rules for how and in what order words are put together into sentences. When these rules differ between the first and second languages, the composition becomes more difficult. 

Physical-Physical factors can affect both spoken and written language. Even in the first language, defects in the vocal cords, tongue, mouth, and other facial muscles can cause setbacks. When a student has a physical disability affecting speech, identifying the impairment, and adding support to help is paramount in language acquisition. Also, the physical environment, such as the ability to arrive at school well-rested and with adequate nutrition can affect the learner in not only speech but all aspects of learning. 

Cognitive- A student's ability to focus and their capacity to remember what they have learned play a large part in the difficulty the student will have in becoming fluent in the new language. Also, diagnosable factors, such as ADHD, can go overlooked. The inability to pay attention can make language learning much harder.

Political- When politics, namely wars in other countries, cause students to leave their homeland, language acquisition is affected. This becomes a time when the learner is taking on the new language out of necessity rather than desire. Also, the directives for how and when to teach English come from a state or sometimes federal level. The way legislature and administration choose to design the curriculum can often conflict with the good of the individual student.