There are several witnesses who will testify for the defence.

有几名证人愿意为被告作证。

《牛津词典》

His friends will testify for him.

他的朋友们将为他作证。

youdao

This will testify for me that I was not idle, and that I spared no pains to bring to pass whatever appeared necessary for my comfortable support.

这可以证明我并没有偷懒，凡是可以使我生活舒适的事情，只要看来有必要，我都不辞劳瘁地把它完成。

youdao

During a trial, lawyers for the opposing sides question the witnesses who testify.

VOA: special.2009.08.31

Geithner is scheduled to testify to Congress on Thursday, where he will outline the Obama administration's proposals for an overhaul of the nation's financial regulatory structure.

VOA: standard.2009.03.25

Meanwhile, a hearing will determine if FBI agent Frederic Whitehurst can testify for the defense.

CNN: Prosecution rests rebuttal case in Simpson trial

This was Koenig's response when asked why he pled guilty and agreed to testify for the prosecution.

FORBES: Magazine Article

Two defense witnesses were allowed to testify for Suu Kyi during the trial.

CNN: Aung San Suu Kyi verdict delayed