を, pronounced as "o" by most speakers, is used primarily to mark the direct object of a sentence. This lesson will solely be about this main primary usage, but do know that there are other usages.
を marks a direct object with transitive verbs. A direct object is what is being acted upon. In the sentence "I threw a rock", rock is the direct object. A transitive verb is a (willful) act that takes a direct object. を may mark a direct object once per clause (part of a sentence). There can be more than one in a sentence, but there should only be one per clause. For now, we're not even at the point of dealing with things like sub-clauses and what not, but when we do, the utility of this statement versus "only one を" will become clear.
Particle Notes: がを X をが X. Something can't simultaneously be a subject and object. は + を makes をば, which is old-fashioned and replaced with just は. を is often casually dropped.
To sell a book.
To type on a word processor.
To eat cake.
To throw a rock.
Word Note: 岩 is the kind of rock that is large and difficult to carry. Use 石 instead.
To sweep the floor.
To erase a blackboard.
To aim for victory.
To boil water.
Word Note: The word for hot water, お湯, should be used instead of 水 because boiling water is hot.
I found money.
10a. 日本語を分かる。 X
10b. 日本語が分かる。 〇
I understand Japanese.
Grammar Note: ～を分かる is starting to be used rarely by the younger generation due to Western influence, and you may see it often when more stuff is added to the verb. However, traditionally, you do not use the particle を with 分かる. Instead you must use が to mark what would be the direct object in English. The reason behind this has to deal with transitivity, which we'll cover later on.
11. 時間｛が 〇・を X｝要る。
Time is needed/(I/we) need time.
To watch TV.
To read a book.
To drink coffee.
To study Kanji.
Practice: Translation the following.
1. To throw a stone. 2. To sing a song. 3. To drink wine.
1. What is a direct object?
2. What is wrong about 岩が投げる?
3. What is wrong about 犬がを飼う?
4. The verb to wait, 待つ, is transitive in Japanese. So, how do you say, "I'll wait for you".
5. Why does を normally not have a translation?