How to Compare Phoneme Inventories Between Languages
One of the most revealing things you can do in linguistics is place two language phoneme inventories side by side. Shared sounds illuminate genetic relatedness or areal contact; divergent sounds explain the characteristic accents speakers carry into a second language. The process of comparing inventories is systematic—and with the right tools, surprisingly accessible even without formal training.
What You Are Comparing
A phoneme inventory is the set of sounds that a language uses contrastively: swapping one for another changes meaning. English /p/ and /b/ are both in the inventory because pin and bin are different words. English /p/ and its aspirated variant [pʰ] are not different phonemes—they are allophones of the same phoneme, since no pair of English words differs only in aspiration. When comparing inventories, always compare phonemes (contrastive categories) rather than phones (raw sounds), or you will overcounts sounds that languages treat as the same.
Using the Comparison Tool
Our IPA Chart lets you explore the full inventory of any individual language, and the language comparison pages allow you to view two inventories side by side, with shared phonemes highlighted. You can immediately see, for example, that English and Mandarin share stops and fricatives but diverge radically in tone—Mandarin has four lexical tones; English has none. Conversely, English has the dental fricatives /θ/ and /ð/ (as in think and the) that are entirely absent from Mandarin.
These gaps predict second-language difficulty. A Chinese learner of English must acquire /θ/ from scratch, since nothing in Mandarin phonology approximates it. An English learner of Mandarin must learn to perceive and produce four pitch categories without conflating them with sentence-level intonation. Understanding the inventory gap is the first step in designing targeted pronunciation instruction.
Beyond Simple Counts
Do not mistake a larger phoneme count for a more complex language. A language with 40 phonemes may have very simple syllable structure, while one with 20 phonemes may permit clusters of five consonants at the start of a syllable (Georgian has words like mts'vrtneli). Inventory size is one dimension; distributional complexity, allophonic richness, and phonological processes are others. Our inventory rankings give you the size dimension; the individual language pages fill in the rest.