Question

[leonl]

ぼくはにほんごをべんきょうするのがだいすきで。
なつにたくさにほんごをべんきょういしています

I Love studying japanese. This summer I'm studying alot of Japanese

How can I connect these sentences

[Yudan Taiteki]

Delete the period.

(I don't know if that で in the first sentence was supposed to be a です, but で is a good connector here.)

[richvh]

ぼくはにほんごをべんきょうするのがだいすきで。
なつにたくさにほんごをべんきょういしています

I Love studying japanese. This summer I'm studying alot of Japanese

How can I connect these sentences

You have a couple of typos (one probably the IME's fault; you have to type "nnni" or "n'ni" to get んに):
なつにたくさんにほんごをべんきょうしています