(someone) constantly has to (do something)

Use this phrase to talk about something that you have to do all the time.

Having kids isn't easy. You constantly have to chase after them.

You'll also hear people use the word "constantly" after "to":

I had to constantly check up on them to make sure that they weren't messing it up.

The word "constantly" means without stopping, and without any breaks. However, people are sometimes exaggerating when they use the word "constantly".

to be (doing something)

Some sentence structures require you to use an infinitive ("to" + a verb). For example:

I want to leave.

She told me to call her.

When you need to use an infinitive, but you also want to talk about an ongoing action, use the form "to be ___ing"):

I told you to be waiting for me when I arrived.

On a day like this, I don't want to be sitting in a dark office. I want to be laying out in the sun.

keep pace with (something)

"Keeping pace" with something means moving quickly enough so that you don't get left behind.

You can use this phrase to talk about someone's actual speed:

I couldn't keep pace with the rest of them, so I told 'em to go on ahead without me.

Or you can talk about "keeping pace" with how quickly things change, like:

Technology changes so quickly; it's pretty much impossible to keep pace with it all.

They have some old-fashioned ways of thinking. I guess that you could say that they haven't kept pace with a lot of the societal changes that have been going on over the last few decades.

the latest developments

"The latest developments" means thing that have just recently changed.

We talk about "the latest developments" in ongoing news stories:

Have you heard the latest developments in the bank scandals?

There can also be "developments" in gossip:

So what are the latest developments with Jim and Lisa?

And industries and professions have "developments" in technology, the competitive landscape, and so on:

Always try to keep up with the latest developments in your field.