Speech
F for Th: Why Your Child Says "Fink" for "Think"
Why children swap f, s or t for th ("fink", "sink" or "tink" for think), when th usually arrives, a quick check you can do at home, the tongue-out cue, and th and f, th and s and th and t minimal pairs with free picture cards.
Th is one of the last sounds children learn, so saying f for th (“free” for three), s for th (“sink” for think) or t for th (“tree” for three) is common for years. Most children master the th in thin by about 6 to 7. The pairs below practice the difference, and every tip comes back to one idea: th is the sound made with the tongue out, peeking between the teeth, where f, s and t are all made with the tongue in.
Why do kids say f, s or t for th?
Children swap th for a sound that is easier to make and sounds close to it. F for th is the most common: “fumb” for thumb, “free” for three. The speech sound activities from MyHealth Alberta, presented by a pediatric speech-language pathologist, name it directly: “Another common mistake is making the ‘f’ sound instead of ‘th.’”
S for th (“sink” for think) is the same mix-up as a lisp in reverse, and t or d for th (“tree” for three, “dat” for that) is stopping, one of the patterns young children use while they learn to talk.
When is th usually mastered?
The th in thin is the last English consonant most children master, by about 6 to 7. A 2020 review of English consonant acquisition by Crowe and McLeod found 90% of children had the th in thin by 6;0 to 6;11, years and months, and the th in that by 5 years 11 months. MyHealth Alberta gives “by 7 years of age”.
So a 5-year-old saying “fumb” is usually on schedule. Ask a speech-language pathologist if it is still there well past 7, or if you are worried. ASHA ProFind lists certified speech-language pathologists.
Quick th check
This is an at-home screening, not a diagnosis, and it does not replace an evaluation by a speech-language pathologist. Ask your child to name ten pictures or things: three, thumb, think, thorn, thread, teeth, bath, moth, mouth and path. Note what you hear in place of th: f, s, t, or the th itself. Read it by age: before 6 or 7, f for th is usually still part of learning to talk.
How do I teach th at home?
Teach th with the tongue out and a gentle blow, in front of a mirror. MyHealth Alberta’s cue is “stick your tongue out between your teeth and gently blow”.
Put the tongue out
Show your child how you put the tip of your tongue out a little, between your teeth. Use a mirror so they can see your tongue and theirs.
Blow gently
Keep the tongue there and blow gently. That soft stream of air is the th in thin. For the th in this, do the same and turn your voice on.
Practice with the pairs
Lay out a pair such as thin and fin. Say one and let your child point, then swap roles. Point to the one you heard, not the one they meant.
Th and f minimal pairs
Th and f minimal pairs are words that differ only in th against f, the mix-up behind “free” for three. Picturing both words is hard, so some of these pictures carry an arrow or a scene. Tap a sound or a word to hear it.
| Th | F |
|---|---|
| thin | fin |
| thought | fought |
| thrill | frill |
| threes | freeze |
| thirst | first |
| wreath | reef |
Th and s minimal pairs
Th and s minimal pairs practice the difference between the tongue out (th) and the tongue behind the teeth (s).
| Th | S |
|---|---|
| think | sink |
| mouth | mouse |
| bath | bass |
| moth | moss |
Th and t, th and d
Th and t pairs practice th against a stopped sound. Th and d pairs do the same for the buzzing th in this and that, but those words cannot be pictured, so they are for saying aloud.
| Th | T |
|---|---|
| three | tree |
| path | pat |
| bath | bat |
To say aloud (th against d): they and day, then and den, though and dough, there and dare.
Voiced and unvoiced th
English has two th sounds: a quiet one, just air, in thin and bath, and a buzzing one with the voice on in this and mother. The th word lists teach both for reading and spelling, with a sort that asks a child to tell them apart by ear.
Th games and activities
These games practice hearing th before saying it.
- Same or different. Read two words, such as three and free, or three and three; your child says whether they sound the same.
- Mirror check. Say a th word together in a mirror. Whoever’s tongue peeks out first wins the round.
- Go fish and memory with the pair cards.
Free printable th cards and worksheets
Free PDF · no sign-up
Free printable th minimal pairs
Pair cards for th and f, th and s, and th and t with the games on the last page, a circle-the-one-I-say listening sheet for th and f, a same-or-different game that adds the th and d words, and th picture cards sorted by where the sound falls in the word (start, end and middle). The cue cards and a practice log come from the minimal pairs page, and the mouth shape cards for every sound from the English sounds chart. No account, no email.
- Minimal Pair Cards (PDF)13 pairs · 5 pages
- Circle the One I Say (PDF)6 pairs · answer key included · 2 pages
- Same or Different? (PDF)10 pairs · answer key included · 2 pages
- Articulation Picture Cards (PDF)17 cards for Th · 4 pages
- Speech Sound Cue Cards (PDF)7 sounds · 4 pages
- Mouth Shape Cards (PDF)46 sounds · 9 pages
- 5-Minute Speech Practice Log (PDF)5 days · 1 page
Frequently asked questions
How many th minimal pairs should children practice?
Three to five pairs at a time is plenty for home practice, for about five minutes. Start with the pattern your child uses, such as f for th, and add pairs as the first ones get easy. A speech-language pathologist may choose a different number for therapy.
Fun games for practicing 'th' vs 'f' sounds at home
Same or different is the simplest: say two words such as three and free and let your child say whether they sound the same. Go fish and memory with picture cards work too, and a mirror game, where you both check the tongue is peeking out, makes the th itself fun.
What age group benefits most from TH and F minimal pairs picture cards?
Children from about 4 to 7. Th is one of the last sounds children master, often not until 6 or 7, so saying f for th at 4 or 5 is usually on time. Pairs help a child who is still saying f for th after that, or one whose speech-language pathologist has suggested them.
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