Input hypothesis

People can learn to speak in new ways.

We learn by listening and reading. It helps to hear things we know. We also need to hear things that are a little new. This helps our brains grow.

There are two ways we pick up words. One way is natural and happens without us trying. The other way is like school work. We learn rules and grammar in class.

Some rules act like a check. We use them to fix our speech. This can slow down our talking.

Learning is also about how we feel. If we feel scared or bored, it is hard to learn. We learn best when we feel happy and safe.

It is okay to be quiet at first. We learn more when we feel good about ourselves.

How do we learn a new language? A man named Stephen Krashen has five ideas about this.

His main idea is called the input hypothesis. It says we learn by hearing or reading things we can understand. We need to hear things that are just a little bit new. He calls this "i+1." The "i" is what we already know. The "+1" is the next step of new words or rules.

Krashen says there are two ways to gain language skills. One way is acquisition. This is a natural way that happens without us trying. It is like how children learn their first language. The other way is learning. This is a conscious way, like studying rules in school.

He also has the monitor hypothesis. This says that the rules we learn act like a monitor. We use them to check our speech for mistakes. However, using a monitor can slow down our talking.

Finally, he talks about the affective filter. This is a mental block caused by feelings. If we feel scared, bored, or stressed, it is hard to learn. We learn best when we feel safe and happy.

Caption: A chart showing the input hypothesis ideas.

How do we truly learn a new language? A linguist named Stephen Krashen has spent years studying this big question. In the 1970s and 1980s, he developed a group of five ideas called the monitor model.

These ideas help us understand how people pick up new ways of speaking. His most famous idea is called the input hypothesis. It suggests that we grow our language skills by understanding messages we hear or read. This is called comprehensible input. It is the main way we build our ability to use a language.

To make progress, the input must be just right for the learner. Krashen uses a special term for this called "i+1." The "i" stands for the language a person already knows. The "+1" represents the next small step of new information.

This new part must be slightly more advanced than what they currently know. It is not enough to just hear any random words. The learner must be able to understand the meaning through the context. This context includes things like knowing the situation or how the world works.

Krashen says there are two very different ways to gain language skills. The first way is called acquisition. This is a natural and subconscious process. It happens without us even realizing it is occurring. This is very similar to how young children learn their first language. The second way is called learning. This is a conscious process that often happens in a school. In this way, students study abstract rules and grammar. Krashen believes that acquisition is much more effective than formal learning.

He also describes how we use the rules we study. This is known as the monitor hypothesis. The monitor acts like an internal checker for our speech.

When we speak, we use our learned rules to scan for mistakes. This helps us perform self-correction after we say something. However, using a monitor can be a hard job. To use it, you must know the rule and focus on being correct. You also need enough time to think. If you use the monitor too much, it can make conversations very slow.

Finally, our feelings play a huge role in how we learn. Krashen calls this the affective filter hypothesis. This idea says that negative emotions can act like a barrier. If a learner feels stressed, bored, or embarrassed, the filter goes up.

A high filter can block the language from being understood. To help, teachers can create a low-anxiety environment. They can also allow for a silent period where students do not have to speak right away. This helps students feel safe and ready to learn.

The input hypothesis, also known as the monitor model, is a framework for understanding second-language acquisition. Developed by the linguist Stephen Krashen during the 1970s and 1980s, it consists of five distinct hypotheses. These ideas suggest that language is not just something we study, but something we acquire through understanding. The model emphasizes that exposure to meaningful messages is the primary driver of linguistic growth.

At the heart of this model is the concept of comprehensible input (CI). Krashen argues that learners progress when they understand messages that are slightly beyond their current level. He uses the formula "i+1" to describe this process. In this equation, "i" represents the learner's current interlanguage, which includes their existing linguistic competence and extra-linguistic knowledge. The "+1" represents the next increment of new language structure. This new information must be understandable through context, such as knowledge of the world or the specific situation.

To understand how this works, we must look at the acquisition–learning hypothesis. Krashen claims there is a strict separation between these two processes. Acquisition is a natural, intuitive, and subconscious process. It is similar to how children learn their native language by focusing on meaning rather than form. Learning, however, is a conscious process. This often involves formal instruction in a classroom where students study abstract rules and grammar. According to Krashen, only acquisition leads to spontaneous language production.

This leads to the monitor hypothesis, which explains how conscious learning interacts with speech. The monitor is an internal mechanism that uses learned rules to check language output. When a learner speaks, they use this system to scan for errors and perform self-correction. For the monitor to work, three specific conditions must be met. First, the learner must actually know the specific rule. Second, the learner must be focused on correctness rather than meaning. Third, the learner must have enough time to apply the rule.

While the monitor can help with accuracy, it has significant limitations. Using the monitor requires a person to slow down, which can make the flow of conversation painfully slow. If a speaker over-monitors, they may focus so much on form that they exchange very little information. Furthermore, Krashen suggests that the monitor is best used during activities like writing. This is because writing allows more time for precision than spontaneous speech. The monitor is a tool for checking, but it is not the source of language itself.

The model also includes the natural order hypothesis. This states that all learners acquire language structures in a predictable, linear sequence. This order is independent of how easy a feature is to teach. For example, in English, the third-person "-s" (as in "he runs") is easy to teach but is often acquired later in the natural sequence. This hypothesis was supported by morpheme studies conducted by researchers Dulay and Burt. They found that certain linguistic forms are predictably learned before others.

Finally, the affective filter hypothesis addresses the emotional side of learning. The affective filter is a psychological barrier that can impede language acquisition. Negative emotions, such as anxiety, self-doubt, or boredom, cause the filter to go "up." When the filter is high, it acts as a blockage that prevents input from being processed. To lower the filter, teachers can create low-anxiety environments. They might also allow for a "silent period," where students are not expected to speak until they have received enough input.

Krashen's work has had a massive influence on language education, especially in the United States. However, the model has also faced criticism from academics. Some critics argue that the hypotheses are untestable through scientific means. Others suggest that the theory assumes a separation between acquisition and learning that may not actually exist. Despite these debates, the idea of comprehensible input remains a central concept in how we think about mastering new languages.