本 and 此: written “this” (本公司, 此事)
【六03】指示代词 / pronouns
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
本 and 此 are two written demonstratives that attach straight to a noun, with no measure word: 本公司, 此事. They are the formal versions of 这 + measure word (这个公司, 这件事).
本 points to what belongs to the speaker or the speaker's institution, or to the current period: 本公司 (our company), 本人 (I myself), 本次 (this time). It is the “our” of contracts, notices and speeches. 此 is a neutral “this” that picks up what has just been mentioned: 此事 (this matter), 此处 (here), 此次 (this time), 此前 / 此后 (before / after this). You already know 此外 (hsk4).
In short: 本 says “ours, the present one”, 此 says “the one we just talked about”. You meet them in notices, contracts, speeches and formal emails; between colleagues at the coffee machine you would say 我们公司, 这件事, 这次. For the other written / spoken pairs, see 书面语 vs 口语 (hsk5-g28).
Examples
本公司成立于二〇一〇年，总部在深圳。
Běn gōngsī chénglì yú èr líng yī líng nián, zǒngbù zài Shēnzhèn.Our company was founded in 2010 and has its headquarters in Shenzhen.
此事我已经知道了，谢谢你的提醒。
Cǐ shì wǒ yǐjīng zhīdào le, xièxie nǐ de tíxǐng.I already know about this, thank you for the reminder.
请在此处签字，一式两份。
Qǐng zài cǐ chù qiānzì, yí shì liǎng fèn.Please sign here, in duplicate.
本次会议的主要内容是讨论明年的计划。
Běn cì huìyì de zhǔyào nèiróng shì tǎolùn míngnián de jìhuà.The main item of this meeting is to discuss next year's plans.
本人对此事不发表意见。
Běnrén duì cǐ shì bù fābiǎo yìjiàn.As for me personally, I have no comment on this matter.
此前双方已经谈过两次，此次的目标是签订合同。
Cǐqián shuāngfāng yǐjīng tán guo liǎng cì, cǐ cì de mùbiāo shì qiāndìng hétóng.The two sides have already talked twice before; the aim this time is to sign the contract.
Common mistakes
✗ 本个公司 → ✓ 本公司 (本 and 此 attach to the noun, with no measure word).
✗ 我们在此个会议上讨论过 → ✓ 我们在此次会议上讨论过 / 我们在这个会议上讨论过 (after 此 you put 次 or nothing, never 个).
✗ 我是客户，我很满意本公司的服务 → ✓ 我很满意贵公司的服务 (本 always means the speaker's own company, the other side's is 贵公司).