The particle は is called “topic marker” and it can mark both the subject and object of a sentence. You might wonder how you can tell if it is marking a subject or object. You can tell from the relation with other particles in the sentence, because usually は will not be used more than once in one clause. However sometimes it does lead to a confusing or unintelligible sentence.
は can be combined with other particles and that’s when it can get a little complicated. The common effect of は is to highlight and emphasize the word it is attached to. As you see in the below examples, は is often used in negative sentences as in “A is B, but C is not B”.
The below are the most common particle combinations that include は. In some cases は is optional add-on, while in some cases は cannot be omitted.
ては
ては is constructed as [verb連用形+接続助詞て+は]. ては is often used in “it is not good/acceptable if you …” sentences, which are often translated in English as “don’t do …”.
- ここでタバコを吸ってはいけない -> It is not OK for you to smoke here. You cannot smoke here
- 中を見てはいけない -> It is not OK if you look inside. Don’t look inside
- 錠剤を噛んではいけない -> Don’t chew the pills (て becomes voiced で after ん)
- 他人に見られては不味い -> It is not good if someone sees us. We can’t be seen
～しては is used to suggest some action.
- 一度やってみてはどうですか？ -> Why don’t you give it a shot?
は is never omitted in the above constructions.
On the other hand は is optional in the below:
- 毎日練習してはいるが、あまり上達しない -> I do practice every day, but I am not improving much
- もう一度考えてはみたが、やはり賛成できない -> I did give it one more thought but I still cannot agree
ては becomes ちゃ, では becomes じゃ in informal conversation, regardless of sentence constructions.
- ここでタバコを吸っちゃいけない
- 一度やってみちゃどう？
では
There are two types of では with different constructions. The first one is [noun+格助詞で+は]. See で for its various meanings. This は is for highlight/contrast and is optional.
- 金で買える物と金では買えない物がある -> There are things you can buy and you cannot buy with money
- 彼は世界選手権で勝ったがオリンピックでは勝てなかった -> He won in the world championship but couldn’t win in the Olympics
- 彼は一人で暮らしているが、私は一人では暮らしていけない -> He lives his life by himself, but I can’t
- 改築は数週間で出来るが、新築は数週間では出来ない -> Remodeling can be done in several weeks, but rebuilding can’t
The second one is [noun+助動詞だ+は]. は before ない is never omitted, while は before ある is optional.
- これは本物ではなくて偽物だ -> This is not a real thing but a fake
- 鳥は脊椎動物ではあるが哺乳類ではない -> Birds are indeed vertebrates but not mammals
では becomes じゃ in informal conversation for both constructions.
- 金じゃ買えない物がある
- 私は一人じゃ暮らしていけない
- これは本物じゃない
とは
とは is constructed as [格助詞と+は]. This は is for emphasis/contrast and is optional
- この映画はそれ程良いとは思わない -> I don’t think this movie is that good
- こういう映画は好みではないけど、よく出来ているとは思う -> This kind of movie is not my thing, but I do think it is well made
- 彼はいろいろ文句を言ったが、駄目だとは言わなかった -> He complained a lot, but didn’t exactly say no
- 私は彼とは気が合わない -> I don’t get along with him (but I do with other people)
- 私は彼とは違ってそういう事はしない -> I’m definitely different from him and would never do such thing
には
には is constructed as [格助詞に+は]. This は is for emphasis/contrast and is mostly optional.
- それは彼の問題で私には関係無い -> That is his problem and has nothing to do with me
- 自転車を車に入れたようとしたが、私の車には入らなかった-> I tried to load a bicycle in my car, but it didn’t fit (but it will in a bigger car)
- 沢山に来てもらいたいが、彼には来てもらいたくない -> I want many people to come but not him
- 予定通りには行かなかった
- ずっと勝っていたが、最後の最後に逆転された -> They led all the way, but lost in the very last minute
- 格上の相手に善戦したが最後には負けた -> They fought well against a better opponent but lost in the end (as expected)
In the below example は cannot be omitted because the contrast is the main point of the sentence:
- それは大人には簡単だが子供には無理だ -> That’s easy for adults but impossible for kids
としては
としては is constructed as [格助詞と+連用形 of する+接続助詞て]. This は is for emphasis/contrast and is optional.
- このマスクは防塵用として使われるが、医療用としては使えない -> This mask is used for anti-dust, but cannot be used for medical applications
にしては
にしては is a set phrase and は is never omitted. にしては is used in “A is B despite C” sentences.
- 十一月にしては温かい -> It is (unusually) warm for November
- この子は年にしては背が高い -> This kid is tall for his age
はしたが
はしたが is constructed as [verb連用形+はしたが] and は is never omitted. はしたが is used in “even though I did A …” sentence.
- 色々試しはしたが、良いものが見つからなかった -> I tried many but couldn’t find one that was good