N5 Grammar · Test 59

で marks the means or language by which an action is performed. 日本語で話しましょう means 'Let's talk in Japanese.' で is the standard particle for indicating the language or tool used for an action.

• 1へ indicates direction toward a destination, not the means/language of an action.
• 3と means 'with' (together with someone) or 'and'; 日本語と話しましょう would imply talking together with Japanese, which makes no sense.
• 4に indicates a target or destination point; it does not express the means or language of an action.

• 日本語にほんご — Japanese language
• 話はなす — to speak/talk

ぐらい (くらい) indicates an approximate amount or duration. 30分ぐらいまちました means 'I waited for about 30 minutes.' It pairs naturally with a duration like 30分 to express 'about ~ minutes.'

• 1ごろ is used for approximate clock times (e.g., 3時ごろ 'around 3 o'clock'), not for durations like 30分.
• 2など means 'things like / such as' and is used to give non-exhaustive examples, not to express approximate quantity.
• 3しか means 'only' and requires a negative predicate (e.g., 30分しかまちませんでした 'I waited only 30 minutes'). Since the verb is affirmative (まちました), しか cannot be used.

• 30分（さんじゅっぷん） — 30 minutes
• まつ — to wait
• バス — bus

で is the て-form (te-form) of the copula だ, used to connect a na-adjective to another adjective. げんきでおもしろい人です means 'is an energetic and interesting person.' げんき is a na-adjective, so its te-form is げんきで, which links it to the next adjective おもしろい.

• 1に cannot connect two adjectives in this way; it would create an ungrammatical phrase (げんきにおもしろい).
• 3だ is the plain copula and cannot directly connect to another adjective (げんきだおもしろい is ungrammatical).
• 4や is used to list nouns in a non-exhaustive way (AやB 'A and B among others'), but here we need to connect a na-adjective to an i-adjective, not list two nouns.

• 先生せんせい — teacher
• げんき — energetic; healthy (na-adjective)
• おもしろい — interesting; funny (i-adjective)

The i-adjective いい (good) has the irregular past form よかった. Adding です makes it polite: よかったです. きのうは天気がよかったです means 'Yesterday the weather was good.' This is the correct polite past form of いい.

• 1いいでした incorrectly attaches the copula past でした directly to the present-form adjective いい. The adjective itself must be conjugated to its past form (よかった), not left as いい.
• 2よかったにです inserts an unneeded に between the adjective past form and です, making it ungrammatical.
• 3いかったです uses an incorrect past form. いい does not become いかった; its correct past form is よかった (an irregular conjugation).

• きのう — yesterday
• 天気てんき — weather
• いい — good (i-adjective; past form: よかった)

ないで is the negative te-form used to express 'without doing X.' コーヒーにさとうをいれないで飲みます means 'I drink coffee without putting sugar in it.' The ないで form connects the negative action to the main verb 飲みます, indicating the action is done without the preceding action.

• 1いれない is simply the plain negative form and cannot directly connect to another verb (飲みます). A connecting form (te-form) is required.
• 2入れなく is not a complete or grammatical connecting form. The proper negative te-forms are ないで (for 'without') or なくて (for reason/cause).
• 4入れなくて is the なくて form, which expresses a reason or cause ('because I didn't put in sugar'), not 'without putting in sugar.' For the meaning 'without doing X,' ないで is the correct form.

• コーヒー — coffee
• さとう — sugar
• 入いれる — to put in; to add
• ないで — without doing ~ (negative te-form)

はやくして is the correct form. はやく is the adverbial form of the い-adjective はやい, and して is the て-form of する. はやくしてください means 'please hurry up' or 'please make it quick.' The pattern 〜くして + ください requests that someone do something in a certain manner.

• 2はやくになって is ungrammatical. はやくなる (to become early/fast) would be the correct intransitive form for an い-adjective, but はやくになる is not standard, and になってください ('please become early') is semantically odd—you cannot ask someone to 'become' early.
• 3はやいにして is ungrammatical. The い-adjective stem はやい cannot be followed by にして in this way. The correct adverbial form is はやく, not はやいに.
• 4はやいになって is doubly wrong: はやい should be はやく (adverbial), and になって is the wrong verb form for this request pattern.

• はやい（早い/速い） — early, fast
• 〜くする — to make something ~ (adverbial form of い-adjective + する)