At a glance
もっとも starts a second sentence that adds a small qualification or afterthought to what was just said, like "mind you", "though" or "having said that". The first statement stays mostly true.
A。もっとも、B（が／けど）。
この店の料理はおいしい。もっとも、値段は少し高いが。 The food at this restaurant is good. Mind you, it's a bit expensive.
How to form it
もっとも is a connector. It goes at the start of the second sentence.
| Position | Pattern | Register |
|---|---|---|
| Start of second sentence | A。もっとも、B。 | Slightly formal; writing and careful speech |
| With が at the end | A。もっとも、Bが。 | Common in writing and polite speech |
| With けど at the end | A。もっとも、Bけど。 | Conversation |
A comma usually follows もっとも.