In English, the consonants N and M after a vowel are two distinct sounds—unlike Japanese, which often uses ん for both.
Mixing up N and M can lead to confusion:
Let your tongue tip touch the ridge behind your upper teeth and push sound into your nose. Keep lips open.
Bring your lips together, close the mouth, and hum through the nose. Feel vibration at the lips.
Say each pair slowly, then at normal speed. Notice where the vibration changes.
Japanese ん covers both sounds. To sharpen your English ear and mouth, practice na, ni, nu, ne, no with a clear N each time, and contrast with ma, mi, mu, me, mo for M.
Over time, you’ll feel the tongue and lip positions naturally.
—Symeon