Phonics Sight Words: What Are Tricky Words and How Should You Teach Them?

Let’s untangle the terminology first, because it trips up even experienced teachers. Three terms get thrown around almost interchangeably, but they don’t mean the same thing.

Sight words refers to any word a reader can recognise instantly, without needing to decode it letter by letter. In that sense, every word eventually becomes a sight word. “Cat” is a sight word for most adults. You don’t sit there going c-a-t anymore. You just see it and know it. So technically, sight words aren’t a fixed list. They’re an outcome of reading practice.

High-frequency words are the words that appear most often in written English. Words like “and,” “the,” “he,” “to,” “go.” Many of these are perfectly decodable. “And” follows standard phonics rules. So does “go.” A child who knows their letter sounds can work these out without help. They show up constantly, though, so children need to recognise them quickly to read fluently.

Tricky words (sometimes called “irregular words”) are the ones that actually break the rules. “Said” doesn’t sound the way it looks. Neither does “one.” Or “was.” These can’t be fully sounded out using the phonics patterns a child has learned so far, so they need to be taught explicitly.

Here’s where it gets confusing. Some high-frequency words are also tricky words (“the,” “was,” “said”), but many aren’t (“and,” “he,” “go”). And some tricky words aren’t particularly high-frequency (“eight,” “upon”). The categories overlap but they’re not the same circle.

Take the word “said.” A child who knows the sounds /s/, /a/, /i/, /d/ would try to read it as “sa-id.” Two syllables. Rhymes with “maid” maybe. But “said” is pronounced /sed/. The “ai” in this word doesn’t follow the pattern. It just doesn’t.

Or look at “one.” By phonics rules, that should be something like /o-n-e/. “Oh-neh.” Not even close to “wun.”

Now look at “go.” Fully decodable. No tricks. But it appears in nearly every beginner text, so a child needs to recognise it instantly.

In the BOOKR Phonics Library, we call them all “tricky words” and teach them in the same flashcard sets. There’s a practical reason for this: from a young learner’s perspective (especially an ELL/ESL learner), the challenge is the same. Whether a word is genuinely irregular or just so common that it needs to be recognised on sight without slow decoding, the child needs to see it, hear it, and practise it until it clicks.

Separating words into “these are high-frequency but decodable” and “these are truly irregular” is a useful distinction for teacher training. But for a five-year-old trying to read a sentence, what matters is whether they can recognise the word quickly enough to keep reading without losing the meaning of the sentence. The BOOKR tricky word sets include both categories because both need the same kind of targeted, repeated, multisensory practice to stick.

So what do you do with these words?

Here’s the thing. Native English-speaking children have heard most of these words thousands of times before they ever see them in print. When a child in London or Sydney encounters “the” or “was” in a book for the first time, they already know the word. They just haven’t seen it written down yet. The connection between the printed form and the spoken word they already own happens fairly quickly.

ELL/ESL learners don’t have that advantage.

A child learning English as a foreign language might be encountering “said” as both a new spoken word AND a new written word at the same time. That’s a double load. They need to learn what it means, how it sounds, and what it looks like on the page, all in one go. And the spelling actively works against them because it doesn’t follow the rules they’ve been taught.

This is why a structured approach to tricky words matters even more in EFL classrooms. You can’t just wave at these words in passing and hope they stick. Research from the National Reading Panel (2000) consistently shows that explicit, systematic instruction outperforms incidental exposure, and that holds doubly true for irregular words taught to non-native speakers.

You’ll sometimes hear people frame phonics and sight words as competing approaches. The “whole word” method versus the “phonics” method. As if you have to pick a side.

That’s a false choice. And it’s actually harmful when it gets into teachers’ heads.

A good phonics programme doesn’t pretend every word is decodable. It acknowledges that some words break the rules, teaches those words explicitly, and moves on. The phonics instruction doesn’t stop. The tricky words get layered in alongside it.

Think of it this way. If phonics is the engine of your reading programme, tricky words are the handful of custom parts you install by hand because they don’t fit the standard assembly line. You still need the engine. But you also need those parts, or the car won’t run.

The BOOKR Phonics Library takes exactly this approach. Tricky words are introduced strategically at each phase, matched to the point where students are developmentally ready to handle them. They don’t replace phonics instruction. They complement it.

Not all at once. That’s the first rule.

Dumping sixty irregular words on a child in Week 3 would be madness. The whole point of systematic phonics is that learning is sequenced, building on what came before. Tricky words follow the same logic.

In the BOOKR Phonics Library, tricky words are introduced gradually across four sets, each aligned with a specific phase of the programme. Here’s how it breaks down:

These arrive early because children encounter them in virtually every English sentence: and, a, the, I, he, she, me, we, be, was, to, do, are, all, no, go.

Sixteen words. Most are extremely short. Several are partially decodable (“he” and “she” follow patterns students already know), while others like “the” and “was” are genuinely irregular. Introducing them at Phase 2 means children can start reading simple sentences almost immediately, even with a small phonics toolkit. That matters more than people realise, because nothing builds reading confidence like actually reading.

By Phase 4, students have learned single letter sounds and moved into digraphs. The second tricky word set reflects this growing competence: you, your, said, here, there, they, so, my, by, were, like, only, have, give.

Some of these are partially decodable at this point. “Like” follows the Magic E pattern students will meet soon. “Have” looks like it should follow that pattern too but doesn’t (the /a/ is short, not long). “Said” is the classic curveball we mentioned earlier. Fourteen more words for the toolkit. Students are starting to build real reading fluency.

Phase 6 brings in the question words and some number words: what, when, why, where, who, which, any, many, more, other, one, two, four, eight.

Notice the pattern here. Nearly all the question words start with “wh,” which at least gives students a visual anchor. But then you’ve got “one” (why is there a W sound?), “two” (silent W), “eight” (the “eigh” combination is irregular at this level), and “four” (that “ou” doesn’t sound like it does in “out”). Fourteen words, and most of them are words students will need constantly.

The final set introduces words with more complex patterns: mother, father, every, after, also, upon, once, could, should, would, right, goes, does, their.

“Could,” “should,” and “would” are a nightmare trio. Silent L in all three. “Does” looks like it should rhyme with “goes” but doesn’t. “Their” and “there” (from Set 2) are homophones with different spellings and meanings, which is the kind of thing that makes English teachers pour a second cup of coffee.

By the end of Phase 7, students will have learned 60 high-frequency tricky words. Combined with their phonics decoding skills, this gives them the tools to read the vast majority of age-appropriate English texts with confidence.

The science of reading research points to a few key principles for teaching phonics sight words. Not all of them are obvious.

Multisensory exposure works. Children who see a word, hear it spoken, say it themselves, and trace or write it form stronger memory traces than children who just see it on a flashcard. The Cambridge ELT White Paper (2020) found that multisensory approaches significantly improved word retention in young EFL learners.

Repetition needs to be spaced, not crammed. Practising “said” twenty times on Monday and then never again is less effective than practising it three times on Monday, twice on Wednesday, and once on Friday. Spaced repetition is one of the most robust findings in memory research, and it applies directly to tricky word instruction.

Context matters. Students who meet a tricky word in a sentence, inside a story, remember it better than students who only ever see it on an isolated card. The word needs to do a job. “He said hello” gives “said” a purpose. A flashcard with “said” floating in white space does not, at least not on its own.

But flashcards still have a role. Particularly for the initial introduction and for targeted practice. The trick is using them as one tool in a larger system, not the only tool.

This is where the flashcard sets come in.

Each phonics story in the BOOKR Phonics Library is paired with a set of interactive flashcards designed for that phase. But the tricky word flashcards are a category of their own. They’re specifically built to help learners see, hear, and repeat high-frequency irregular words through multisensory exposure.

Here’s what makes them different from a stack of paper flashcards taped to the wall:

AI-powered pronunciation assessment. Students listen to a model pronunciation, record their own voice, and get instant feedback. For ELL/ESL learners especially, this is huge. A child practising alone at home can’t ask their teacher “Am I saying ‘because’ right?” But the app can tell them. Immediately.

Built-in audio models from native speakers. Every tricky word includes an authentic pronunciation recorded by a native speaker. Not a robot voice. Not text-to-speech. A real person saying the word naturally. This matters for intonation and connected speech, both of which affect how well a child recognises and produces these words in actual conversation.

Repeatable, self-paced practice. A child who needs to hear “their” fifteen times can do that without holding up the rest of the class. A child who gets it after three listens can move on. The flashcards accommodate both without any extra planning from the teacher.

Aligned to the phonics sequence. The tricky word sets match the programme’s phases exactly. A child working through Phase 4 gets Set 2 tricky words at the right moment, not earlier (when they’d be overwhelmed) and not later (when they’d have been struggling with those words in their reading for weeks already).

A few things that experienced teachers know but textbooks don’t always say.

Don’t drill tricky words in isolation for too long. Write the word on the board, say it, have students repeat it, use it in a sentence, move on. The book will provide the reinforcement. If you spend ten minutes on “because” before reading the story, your students will be bored before they even open the book. Sixty seconds is usually enough for a pre-teach.

Use the “tricky part” strategy. For every tricky word, there’s usually one specific bit that’s irregular. In “said,” it’s the “ai” making an /e/ sound. In “one,” it’s the “o” sounding like /w/. Point that out explicitly. “Most of this word you can sound out. But THIS part is tricky. We just have to remember it.” It reduces the memory load because students aren’t treating the whole word as irregular, just the one bit that breaks the rules.

Let students encounter the word in a story first when possible. Pre-teaching is useful, but there’s also value in letting a child hit a tricky word in context, struggle for a moment, and then get the support they need. That moment of productive confusion (“wait, that can’t be right…”) actually strengthens retention if you resolve it quickly.

And use the digital flashcards for homework. Seriously. This is one of the rare cases where “go practise on the app” is genuinely useful homework rather than busywork. A child spending five minutes with the BOOKR tricky word flashcards at home, listening and repeating, is doing more for their sight word recognition than a worksheet asking them to write “because” ten times.

The terms overlap significantly. “Sight words” is a broader term for any word a reader recognises instantly without decoding. “Tricky words” is more specific, referring to high-frequency words with irregular spellings that don’t follow standard phonics rules. In the BOOKR Phonics Library and many UK-based phonics programmes, “tricky words” is the preferred term. In US contexts, you’ll more often hear “sight words.”

By the end of Phase 7 in the BOOKR Phonics Library, students learn 60 tricky words across four structured sets. Other programmes vary, but most target between 50 and 100 high-frequency words in the early years. The exact number matters less than whether the words are taught systematically and practised regularly.

Both, from early on. Phonics provides the decoding foundation, and tricky words are introduced alongside it as needed. In the BOOKR programme, the first set of 16 tricky words arrives at Phase 2, right alongside the initial letter sounds. You don’t need to wait until phonics is “done” to start teaching tricky words. In fact, waiting would hold students back, because words like “the,” “I,” and “was” appear in almost every sentence.

Yes, partially. Many tricky words aren’t completely irregular. The word “said” has two decodable sounds (/s/ and /d/) and only one tricky part (the “ai” making an /e/ sound). Teaching children to identify the decodable parts AND the tricky part reduces the memory load and builds on their phonics skills rather than abandoning them.

Multisensory approaches work best: see the word, hear it pronounced by a native speaker, say it aloud, use it in context. The BOOKR Phonics Library’s interactive flashcards combine all of these with AI-powered pronunciation feedback, which is especially valuable for ELL/ESL learners who may not have access to native English speakers outside the classroom. Spaced repetition and meaningful context (through stories) are equally important.