～ことは～が— True, But…

• この店は安いことは安いが、あまりおいしくない。

  Kono mise wa yasui koto wa yasui ga, amari oishikunai.

  This restaurant is cheap all right, but it's not very tasty.

  安い is repeated with ことは…が to concede cheapness before the 'but'

• 泳げることは泳げるが、あまり得意ではない。

  Oyogeru koto wa oyogeru ga, amari tokui de wa nai.

  I can swim, sure, but I'm not very good at it.

  泳げる repeated to admit the ability, then qualified

• 読んだことは読んだが、内容はほとんど覚えていない。

  Yonda koto wa yonda ga, naiyou wa hotondo oboete inai.

  I did read it, but I barely remember the contents.

  読んだ repeated to concede the action before the reservation

• ・The same word must be repeated around ことは…が.
• ・The が can be replaced with けど/けれど in casual speech.
• ・Expresses reluctant or partial agreement — 'yes, but with a catch.'

Commonly confused with

The JLPT rarely asks whether you recognise a pattern — it asks which of several similar patterns fits. These are the ones ～ことは～が is tested against.

• に応えて — In Response To / Living Up To
• ～も～ば～も — Both This And That
• ～つつ — While / Even Though
• ～というと／といえば／といったら — Speaking Of
• にかかわらず — Regardless Of / Irrespective Of
• にせよ〜にせよ — Whichever the Case
• にもかかわらず — In Spite of It All
• ～のみならず — Not Only, But Also