Understanding Interlanguage

When learning a new language, learners don’t immediately switch from their native language (L1) to speaking perfectly in the new language (L2). Instead, they create a unique, evolving system called interlanguage. Think of it as a language in progress—something that’s neither exactly their first language nor fully the target language, but somewhere in between. Understanding this concept is essential for teachers because it helps us see learner errors not just as mistakes but as natural steps in language development.

What Is Interlanguage?

Interlanguage is the language system that learners build while learning a second or foreign language. It’s their own version of the language, made up of a mix of correct and incorrect elements, shaped by influences from both their native language and the new language (Selinker, 1972). This means learners don’t just copy their mother tongue or the target language—they create something new, with its own internal rules.

For example, a Spanish speaker learning English might say, “I have 20 years” instead of “I am 20 years old.” This happens because they’re transferring a direct idea from Spanish (“Yo tengo 20 años”) to English, showing how their interlanguage reflects both languages.

The History and Theory Behind Interlanguage

Back in the 1960s and early 1970s, language researchers first focused on Contrastive Analysis, which tried to predict learner errors by comparing the native language and the target language. They believed most errors came from interference—where learners apply rules from their L1 to L2.

However, what really changed the way we understand language learning was the introduction of Error Analysis and the term interlanguage by Selinker in 1972. Instead of just blaming the native language, researchers realized errors can also come from the learner’s own attempts to make sense of the new language’s system—sometimes over-applying rules they’ve just learned (overgeneralization) or simplifying complex structures.

This shift helped “undemonize” errors, showing that making mistakes is a normal, even necessary, part of learning (Selinker, 1972; Ellis, 1994).

Key Characteristics of Interlanguage

Interlanguage is:

• Systematic: It follows rules, even if they’re not the same as the target language’s rules. Learners tend to make the same kinds of errors repeatedly because they’re consistent with their current system.
• Dynamic: It changes constantly as learners improve. Errors that seem common at first may disappear as learners gain more knowledge.
• Permeable: It’s flexible—rules can be modified or replaced as learners receive more input and practice.
• Variable: Interlanguage can change depending on context. A learner might speak differently with friends than in a formal class.
• Reduced: Grammatically, it’s often simpler than the target language, and it may cover fewer communicative functions at first.

For example, a learner might drop the subject pronoun in English (“Is raining”) because Spanish often allows that, but this will likely change as their interlanguage develops.

The Processes Shaping Interlanguage

There are three main processes learners go through while building their interlanguage:

1. Language Transfer (Interference). Learners apply rules from their L1 to L2, which can cause errors. For example, “I have 20 years” reflects Spanish influence. This is very common and expected.
2. Overgeneralization. Learners apply a new L2 rule too broadly, creating errors that native speakers wouldn’t make. For example, saying “I goed home” by adding “-ed” to an irregular verb, much like children learning their first language might do.
3. Simplification. Learners sometimes simplify complex language features to make communication easier. This is similar to how children acquire language.

Fossilization: When Errors Become Habits

Sometimes, learners keep using incorrect forms even after years of study. This is called fossilization. What happens is that an error becomes fixed, and the learner stops noticing or correcting it.

Take the example of many Spanish speakers who confuse the English pronouns “he” and “she.” This error can persist for a long time because it may not seriously affect communication, so the learner doesn’t feel the need to change it.

As teachers, we can help by making learners aware of these fossilized errors—maybe by recording their speech or having them track their written mistakes over time. Awareness is the first step to change (Han, 2004; Selinker, 1992).

Common Errors Spanish Speakers Make in English and Why

Recognizing typical errors helps teachers respond more effectively. Here are some examples with explanations:

• “I have 20 years old.” Reason: Spanish speakers translate directly from “Yo tengo 20 años,” using “have” instead of “be.” This is an example of L1 transfer.
• Preposition confusion: “Let’s meet in your house” Spanish “en” can mean “in,” “at,” or “on,” depending on context, so learners struggle to pick the right English preposition.
• Mixing gender in possessive pronouns. Spanish possessives don’t show gender (“su libro”), but English does (“his book” vs. “her book”).
• Dropping the subject pronoun. Spanish often omits subjects, while English requires them (“Is raining” vs. “It is raining”).
• Using “make” and “do” incorrectly. These verbs appear similar but collocate with different expressions (“make a decision” vs. “do homework”).
• False friends. Words that look similar but differ in meaning (e.g., “embarrassed” vs. “embarazada” meaning “pregnant”).
• Pronunciation issues. English distinguishes short and long vowels (“ship” vs. “sheep”), which Spanish does not, causing confusion.

Exercises to Apply Knowledge

Exercise 1: Identify and Explain Common Errors

Look at learners’ sentences and guess why the error happened. For example:

• “I have a strong headache.”

Correct: “I have a bad headache.”

Reason: “Strong” doesn’t collocate with “headache” in English.

Exercise 2: Match Definitions to Terms

Definition	Term
When L1 affects L2 errors	L1 interference
When incorrect language becomes habitual	Fossilization
Errors natural to learning, like children’s	Developmental error
Using a learned rule in the wrong context	Overgeneralization
Learner’s own language system between L1 and L2	Interlanguage
Words that look similar but have different meanings	False friend

Exercise 3: Error Correction and Analysis

Correct these sentences and explain the errors:

1. “He has not yet gone to the bed.”

Correct: “He has not yet gone to bed.”

Reason: “Go to bed” does not use the definite article “the.”

2. “Does he needs a ticket?”

Correct: “Does he need a ticket?”

Reason: After “does,” use the base form without “s.”

Final Thoughts

Interlanguage shows us that learning a new language is a complex, fascinating journey—not just about avoiding mistakes, but about creating and refining a new system for communication. As teachers, recognizing and valuing this process empowers us to support learners more effectively. We can guide them through their unique path, understanding their struggles and successes as natural and vital parts of language learning.

Remember, every error is a clue, a step forward. When learners feel understood and encouraged, they build confidence to keep moving ahead.

References

• Ellis, R. (1994). The Study of Second Language Acquisition. Oxford University Press.
• Han, Z. (2004). Fossilization in adult second language acquisition. Multilingual Matters.
• Selinker, L. (1972). Interlanguage. International Review of Applied Linguistics, 10(3), 209–231.
• Selinker, L. (1992). Rediscovering interlanguage. Longman.