Learn English – “make sure that” vs “make sure if”

The meaning is broadly the same, but the sentences are not always applicable in the same circumstances.

“I'm sure he will make a good teacher” implies that he is currently not a teacher, and that when (or if) he becomes a teacher, he will be a good one.

“I'm sure he will be a good teacher” is similar, but applies to a definite point in time, whereas “will make” applies to an unspecified (and possibly hypothetical) future time.

“I'm sure he will become a good teacher” implies that he is currently not a good teacher, either because he is currently not a teacher, or because he is currently a bad teacher.

I'm sure he will make a good teacher, if he decides to quit his office job.
I'm sure he will be a good teacher. Let's hire him for the next term.
I'm sure he will become a good teacher, after a few more years' experience. Right now he's mediocre.

Some examples in the wild:

signs your boyfriend will make a good husband [The marriage will turn him into husband, and the question is whether he'll turn into a good husband or a bad husband.]
ways to tell if he'll be a good husband [Same question as the previous one really, but phrased differently. After the marriage happens, he will be a husband; will he be a good one or a bad one?]
will my boyfriend become a good husband? [Here, means the same as the previous two.]
Separate or stay? Is there a chance he'll become a good husband? [Here, he is already a husband, but not a good one.]

The nuances can change if you add a time complement.

I'm sure he will make a good teacher in the fullness of time. But right now, he's mediocre.
I'm sure he will become a good teacher when he completes his education degree.

“Make” carries a sense of achievement, whereas “become” sounds more passive.

In the past tense, the implications are somewhat different for make. “He made a good teacher” makes me think that he is no longer a teacher.

To use X - X here has to be a tool, and to use X will mean do an activity where X will help or is needed to accomplish that activity. E.g.: Use the pen to write down what I say. A pen is a tool that is needed to accomplish writing.

To make use of X - This is like to use X except that X is not necessarily needed to complete the activity in question, but it will help. E.g.: Feel free to make use of anything in my spice rack when you start cooking. The spices might help, but aren't strictly required.

To tap into X - A physical tap is something that allows one to draw out or extract water, liquid, or other similar resource from a stream, network, or container. Following this logic, tapping into something can mean attempting to draw out or extract something needed (from someone) that can help you complete an activity, and this something will not be a physical object but a mental resource such as knowledge, skill, social connections, etc. Tap into your customer service skills when dealing with difficult requests.

So ...

A market in my opinion at least, that can be tapped into. Graduates would more likely be something made use of unless your location is starved for the skills of this specific group of graduates. Tap into X somewhat carries the subtext of X is needed by us but not vice versa.

And,

Can you make use of these papers?

Can you use these papers?

The difference in meaning depends on what the papers contain and how useful they are to the person you are offering to them. If you think they will help, but aren't required, make use of is appropriate. If you think they are needed by him to accomplish his task, use is appropriate.