Forms of ます and verb conjugation

Invitations ～ませんか・～ましょう

The pattern 「〜ませんか」 is formed by adding 「ませんか」 to the masu-stem (masu-stem) of a verb. This pattern is used to invite the listener to do something together, meaning 'how about ...?' or 'would you like to ...?', and it sounds polite and gentle. Example: 「いっしょに 買い物に 行きませんか」 (would you like to go shopping together?). The word 「いっしょに」 (together) often appears with this pattern.

How to form it: 行きます → 行き + ませんか (いきませんか), 食べます → 食べ + ませんか (たべませんか), 見ます → 見 + ませんか (みませんか). The dictionary form (行く), the て-form (行って), and the ない-form (行かない) are not used before 「ませんか」.

The answer to an invitation is usually 「はい、いいですね」 (yes, that's good) or 「はい、いきましょう」 (yes, let's go), that is, agreeing while also inviting in return. The 「〜ませんか」 pattern is also used by a superior to a subordinate in a gentle way.

The pattern 「〜ましょう」 is formed by adding 「ましょう」 to the masu-stem and means 'let's ...'. This pattern is used to invite someone to do something together or to propose an action to be done together, for example after stating a reason. Example: 「今日は 寒いので、あたたかい スープを 作りましょう」 (since it is cold today, let's make some warm soup).

In a family or group context, 「〜ましょう」 is used when the invitation is addressed to all members, often together with the expression 「みんなで」 (all together).

The difference between the two: 「〜ませんか」 asks for the listener's opinion more gently, whereas 「〜ましょう」 expresses a joint invitation more directly. Both differ from other forms that are often confused with them: 「〜ました」 (past), 「〜たいです」 (the speaker's own desire), 「〜でしょう」 (conjecture), 「〜てください」 (request), and 「〜ないでください」 (prohibition).

Destination words with the particle 「に」 are placed before the predicate of the invitation. The verb stem + 「に」 expresses purpose: 「お茶を 飲みに 行きませんか」 (would you like to go out to drink some tea?).

Expressing desire ～たい

The pattern 「〜たい」 is formed with the masu-stem of a verb + 「たい」, followed by 「です」 for the polite form, for example 「食べたいです」 (I want to eat). This pattern expresses the speaker's own desire. Examples of formation: 行きます → 行きたい, 食べます → 食べたい, 寝ます → 寝たい (want to sleep), 登ります → 登りたい (want to climb).

In a sentence, 「たい」 is placed directly after the verb stem, and 「です」 comes at the end of the sentence. Phrases of destination or place such as 「日本へ」 or 「友だちに」 are placed before the predicate: 「週末に 友だちに 会いたいです」 (I want to meet friends on the weekend).

Because 「たい」 follows the pattern of い-adjectives, its form changes: 〜たくないです (do not want to ...), 〜たかったです (wanted to ... in the past), and 〜たくて (connective form). The forms 「たくない」 and 「たくて」 often serve as distractor choices.

In reading passages, the writer's wish to do something in a certain season is also expressed with 〜たい.

To express the desire of a third person, 「〜たがる」 is used instead of 「〜たい」, for example 「弟は 海へ 行きたがっています」 (my younger brother wants to go to the sea). Therefore, 〜たがる is not used for one's own desire.

The question 「〜たいですか」 or 「何が したいですか」 (what do you want to do?) asks about the desire of the listener, and the answer uses 〜たいです.

To express a plan or a hoped-for wish, 「〜たいと 思っています」 (I am thinking that I want to ...) is used. Time expressions such as 「今度は」 (next time) and 「いつか」 (someday) are often used with this pattern.

The 〜たい desire expresses only the speaker's will, so it differs from the invitation 〜ましょう, which invites the listener. When the reason is stated first, the pattern is used like this: 「のどが かわいたので、水を 飲みたいです」 (because I am thirsty, I want to drink water).

Past form ～ました・～ませんでした

The polite past form is made by changing 〜ます to 〜ました (affirmative past) and 〜ません to 〜ませんでした (negative past). This form is used for events that have happened or did not happen in the past, usually together with a time expression such as 「きのう(yesterday)」, 「おととい(the day before yesterday)」, or 「先週(せんしゅう, last week)」. For example, 「見ます(みます, to watch)」 becomes 「見ました(みました, watched)」.