Have you ever pronounced a word in English exactly how you thought it should sound, only to have an American ask you to repeat yourself?

The problem might not be your consonants or your grammar. It might be your vowels.

One of the most confusing things about American English pronunciation is that the same vowel sound can be spelled in several different ways, while similar-looking words can have completely different vowel sounds.

For non-native English-speaking professionals, this can create problems in meetings, presentations, and everyday conversations. You might know exactly what you want to say, but if you're using the wrong vowel sound, your listener may need an extra moment to understand you.

Let's look at one common example: the difference between the vowel sounds in saw and so.

The Difference Between AW and OH in American English

Say these words out loud:

• Saw

• So

• Law

• Low

• Lawn

• Loan

• Flaw

• Flow

• Raw

• Row

• Jaw

• Joe

Can you hear the difference between the two groups?

The first group contains the vowel sound in saw, law, and flaw. The second contains the vowel sound in so, low, and flow.

These are two different vowel sounds in American English, and using one in place of the other can change how clearly a word is understood.

For this article, I'll use AW to refer to the vowel sound in saw and OH to refer to the vowel sound in so. These labels are convenient ways to identify the sounds, not formal phonetic symbols.

How to Produce the AW Sound

To produce the AW sound, focus on three things:

1. Open your mouth.

Your jaw drops, creating more space in your mouth.

2. Let your tongue drop.

Your tongue needs to move into the appropriate low-to-mid position for your accent. Don't raise it into the position you use for the OH sound.

3. Keep your lips relaxed and open.

Don't push your lips forward into a tight, rounded position.

Now practice:

• Saw

• Law

• Flaw

• Raw

• Jaw

Pay attention to what your jaw, tongue, and lips are doing as you say each word.

How to Produce the OH Sound

The OH sound requires a different mouth shape.

Your tongue moves higher, and your lips become more rounded. Depending on your American accent, the sound also involves movement as you transition toward the end of the vowel.

Practice these words:

• So

• Low

• Flow

• Row

• Joe

Now alternate between the two sounds:

• Saw — So

• Law — Low

• Flaw — Flow

• Raw — Row

• Jaw — Joe

Don't rush through the pairs. Your goal is to develop control over the physical movements required for each vowel.

One important note: American accents vary, and some speakers pronounce the vowel in saw differently from others. Some accents also merge the vowels in words such as cot and caught. The exact target should match the American accent you're learning.

Why AW and OH Are Easy to Confuse

One reason these sounds are difficult for non-native English speakers is that the spelling doesn't always make the pronunciation obvious.

If you learned English primarily through reading, you may have developed pronunciation habits based on the letters you see rather than the sounds Americans actually produce.

For example, you might see the word law and pronounce it with the vowel sound in low. Or you might see saw and use the same vowel sound you use in so.

The problem is that English spelling doesn't consistently tell you which vowel sound to produce.

And the confusion doesn't stop with words spelled with AW.

How to Pronounce Words With AU in American English

The letters AU can also represent the vowel sound found in saw in many varieties of American English.

Look at these examples:

• Cause

• Pause

• Sauce

• Fraud

• Auto

• Audio

• Caution

• Laundry

• Automatic

• Authentic

• Audience

• Autograph

In these words, AU generally represents one vowel sound rather than two separate vowel sounds.

For example, cause doesn't have the same vowel sound as cows. Likewise, pause doesn't have the same vowel sound as bows when bows rhymes with cows.

Compare:

• Cause — Cows

• Pause — Pows

• Sauce — Souse

• Auto — Outer

The exact vowel quality can vary by American accent, but the central lesson remains the same: don't assume that each vowel letter represents a separate sound, or that the spelling alone tells you how to pronounce a word.

The Same American English Vowel Can Have Different Spellings

Let's look at an even bigger issue.

The vowel sound in saw can be represented by different spellings, depending on the word.

Here are some examples from common American English pronunciation patterns.

These examples illustrate why you can't reliably learn American English pronunciation by memorizing the sounds of individual letters.

However, there's an important distinction: the same spelling doesn't always represent the same sound across all American accents. Words such as coffee, talk, and caught can vary depending on the speaker's regional accent.

For example, some Americans pronounce cot and caught with the same vowel, while others distinguish them.

The goal is to learn the sound system of your target accent and recognize the pronunciation of individual words, rather than assume every spelling follows one universal rule.

Why American English Has More Than Five Vowel Sounds

You probably learned that English has five vowels: A, E, I, O, and U.

But these are vowel letters, not the total number of vowel sounds in spoken English.

American English has many more vowel sounds than five. Depending on how the sounds are classified and which American accent is being described, a common estimate is around 14–20 vowel phonemes.

Think about the differences between these words:

• Beat and bit

• Bet and bat

• Bat and but

• Cot and coat

• Full and fool

• Saw and so

Changing the vowel can change the word entirely.

This is why learning the American English vowel system is so important if you want to improve your pronunciation and make your speech easier to understand.

You need to know which sounds exist, how they differ, and how to produce them consistently.

How to Improve Your American English Pronunciation

If you want to sound more American, don't limit your practice to listening and repeating words. You also need to understand how to physically produce the sounds.

Here are three areas to work on.

1. Learn the American English Vowel Sounds

Start by identifying the vowel sounds used in your target American accent.

Learn how the sounds differ from one another and which words contain them.

This is especially important if your native language has fewer vowel contrasts than American English. You may be using one familiar vowel sound for several different English vowels without realizing it.

2. Train Your Tongue, Jaw, and Lips

Pronunciation is physical.

Your tongue, jaw, and lips need to move into the right positions to produce the sounds accurately. Simply knowing that two words sound different doesn't necessarily mean you can produce that difference consistently.

Practice the mouth movements slowly before working toward a more natural speaking pace.

For the AW and OH contrast, alternate between pairs such as saw/so and law/low. Pay attention to your jaw opening, tongue height, and lip rounding.

3. Learn Which Words Use Which Sounds

Knowing how to produce a vowel is only part of the process. You also need to recognize which vowel belongs in each word.

English spelling is unpredictable enough that you can't always work this out from the letters alone.

Build your vocabulary around sound patterns, listen to reliable American pronunciation models, and practice words in sentences rather than only in isolation.

For example:

• The law is clear.

• Follow the law.

• Pause the video.

• I bought an automatic coffee machine.

Practice each sentence while keeping the target vowel consistent.

Over time, you want to recognize the correct sound automatically, without having to stop and think about every word.

Want to Sound More American When You Speak English?

If you're a non-native English-speaking professional who wants to communicate more clearly and confidently in American English, mastering the vowel system is an important step.

But it takes more than learning a list of sounds. You need to understand how to produce them physically, identify the sounds in individual words, and apply them consistently in real conversations.

In my one-on-one American accent coaching programs, I work with professionals on the specific sounds and mouth movements they need to improve, with structured practice and personalized feedback.

Ready to work on your American accent?

Explore my private American accent coaching programs and schedule a free 25-minute consultation to discuss your goals and see whether we're a good fit.

You can also explore my self-paced American accent courses if you prefer to train independently.