お前に足りないのは、持久力だよ。の英語

What you lack is stamina.

sustaining power

That can boost my staying power.

lacking necessary force for effectiveness

This stock is probably not sufficient for you, right?

Don't be long.

Your performance has not done full justice to your ability.

There is no shortage of ideas.

Your income disqualifies you

Ability alone is not enough.

I won't keep [detain] you long.

Those parts are always short.

There is always a shortage of those parts.

I have an insufficient academic ability.

I must apologize to you for not writing for so long.

It won't last long.

The length of a day or a year varies but little.

The length of days and the length of years hardly vary at all.

There! That wasn't long, was it?

You've been at it long enough, haven't you?

We're one baton short for the relay.

Some of these young people have legs twice as long as mine.

Juggling with stock is useless in (the) face of the basic shortage.

There is a shortage of good building wood.

I won't be long dressing.

A shortage of personnel does not always cause a drop in efficiency.

How are you doing? I haven't seen you for an age!

It is not enough for you with this description.

I have not heard from him for a long time.

He is capable enough, but lacks experience.