However much vocabulary you learn, you will meet words on JFT-Basic that you have never seen. That is normal, and it is not a disaster.
Most of the time, the sentence around an unknown word tells you enough to answer the question. Working a word out from context is a skill like any other, and it matters most in two places: Script and Vocabulary, where a gap must be filled, and Reading, where an unfamiliar word sits in the middle of a notice.
First: does it matter?
In reading, the first question to ask about an unknown word is whether the question needs it at all. Many do not.
Read the question, find the part of the text it points to, and only then worry about vocabulary. A word you do not know in a sentence the question does not ask about costs you nothing. Skip it and keep going.
Clue 1: the kanji you do know
A compound you have never seen is often made of kanji you have. Put the pieces together.
- 駐車場 - you may not know 駐, but 車 (car) and 場 (place) give you “a place for cars”: a car park.
- 消火器 - 火 is fire, 消 is the 消 in 消す (put out). Something that puts out fires: an extinguisher.
- 工事中 - 中 at the end means “in the middle of”. 工事 is work of some kind. Something is under way.
- 禁煙 - if you know 禁止 (forbidden) and 煙 from たばこ notices, this is no smoking.
You do not need the exact English word. “A place for cars” is enough to answer almost any question about a car park.
Clue 2: what the sentence does with it
The verb, the particle and the rest of the sentence often tell you what kind of thing the word is.
この道は工事中なので、通れません。
Even if 工事中 means nothing to you, 通れません (you cannot go through) and ので (because) tell you it is a reason the road is closed. That is all a question would need.
入口の近くに消火器があります。火事のときは、これを使ってください。
Something by the entrance, to be used in a fire. You have worked out the word from the second sentence alone.
Clue 3: the shape of the gap
In Script and Vocabulary, some questions give a sentence with a gap and ask which word fits. Here the grammar around the gap narrows the options before meaning even comes into it.
さむいので、まどを（ ）ください。 しめて / あいて / つけて
The particle を tells you the verb takes an object, so you need a transitive verb. あいて (from あく, to open by itself) does not take を - and it means the opposite anyway. つけて takes を, but you switch on a light, not a window. That leaves しめて. The pairs behind this are in transitive and intransitive verbs.
Particles are the cheapest clue in the sentence. を, に, で and が each tell you something about the word next to them.
Clue 4: signposts
Connecting words tell you how the unknown word relates to the rest:
- でも / が - contrast. The word means roughly the opposite of what came before.
- から / ので - reason. The word explains what follows.
- たとえば - for example. The examples tell you what the category is.
- や / とか - a list. The word belongs with the other items.
冷蔵庫には、牛乳や卵や豆腐が入っています。
If 豆腐 is new to you, the list tells you it is a food kept in the fridge. For most questions, that is enough.
Clue 5: description questions
Another Script and Vocabulary question type gives a short description and asks which word it describes.
やさいや肉を切って、なべで煮たり焼いたりする人です。
If you do not know the exact word in an option, work backwards. Which option could be a person who cuts vegetables and cooks them? Even a partly known word - a katakana word like コック, or a job word ending in 〜員 or 〜者 - can be matched to the description.
Do not overdo it
Guessing from context is for when you are stuck, not a reason to stop learning words. The more vocabulary you know, the more clues you have to work with - it compounds. See how many words you need and building a personal word list.
And when you have worked a word out during a mock, look it up afterwards and add it to your list. That is how the guess turns into knowledge.
Where to practise
Every one of our ten free mock exams has twelve Script and Vocabulary questions and six reading texts, and each set is themed, so the unfamiliar words differ from paper to paper. Mock exam 6 (agriculture and fishery) and mock exam 10 are good tests of guessing: farm and sea vocabulary is the furthest from most textbooks, and Set 10 is the hardest paper of the ten.
The answer guides, such as the mock exam 6 answers, show which clue in each sentence pointed to the right answer. For the section itself, see the Script and Vocabulary section.